## bookmark_borderJesus: True Prophet or False Prophet? – Part 2

There are three main areas of evidence required to build a rational case for the resurrection of Jesus, for the claim that God raised Jesus from the dead (GRJ):
I. General Background Evidence
II. Prior Historical Evidence
III. Posterior Historical Evidence
A key claim that Christian apologists need to support in relation to Prior Historical Evidence is that Jesus was a true prophet (JTP).  But the evidence we have, on the assumption that the Gospels provide historically reliable accounts of the life of Jesus, clearly supports the OPPOSITE conclusion, namely that Jesus was a false prophet (JFP).  If I am correct that the Gospels provide evidence that makes it very probable that Jesus was a false prophet, then the Prior Historical Evidence part of the case for the resurrection of Jesus is a failure, and thus it will NOT be possible for Christian apologists to build a good case for the claim that God raised Jesus from the dead (GRJ).
1. Jesus claimed to be a prophet.
2. Jesus was not a prophet.
3. IF a person P claimed to be a prophet but was not a prophet, THEN person P was a false prophet.
Therefore:
4. Jesus was a false prophet.
5. IF a person P was a false prophet, THEN it is not the case that God raised person P from the dead.
Therefore:
6. It is NOT the case that God raised Jesus from the dead.
I have dropped explicit references to probability, but the premises are not necessary truths nor is the truth of the premises certain, with the exception of premise (3), which I believe to be an analytic truth.  We don’t know with certainty that Jesus claimed to be a prophet, because there is NOTHING that is certain about Jesus.  Even the existence of Jesus is subject to reasonable doubt.  But to be generous towards the Christian viewpoint, I will grant, for the sake of argument, that the Gospels provide historically reliable accounts of the life of Jesus.  Given that assumption, it is very probable that Jesus claimed to be a prophet.
Given the assumption that the Gospels provide reliable accounts of the life of Jesus, there are six reasons supporting premise (1):
(i) Jesus said things that clearly implied he was a prophet:

• Luke 13:32-34
• Matthew 10:40-42
• John 7:14-17
• John 8:23-28 & 39-47
• John 12:44-50
• John 17:1-19

(ii) Jesus made several bold and confident predictions about the future, speaking as though he was a prophet:

• Mark 1:14-15
• Mark 9:30-32
• Mark 11:1-3
• Mark 13:9-23
• Mark 13:24-31
• Mark 14:61-65

(iii) During his ministry, some of his fellow Jews characterized Jesus as a prophet, and Jesus never objected to this:

• Mark 6:14-16
• Luke 7:11-17
• Matthew 21:10-11
• Matthew 21:43-46
• John 7:40-52
• John 9:16-18

(iv) Jesus was aware that some of his fellow Jews viewed him as a prophet, and Jesus never objected to this view:

• Mark 8:27-28
• Matthew 16:13-14
• John 4:16-26
• John 6:13-15

(v) Some of Jesus’ disciples called him a prophet:

• Luke 24:13-24

(vi) The author of the Gospel of John viewed Jesus as a prophet:

• John 3:31-36

The book of Acts is not a gospel, but it was a companion volume to the gospel of Luke, written by the same author.  So, if we assume that the gospel of Luke provides an historically reliable account of the life of Jesus, then it would be reasonable to assume that the book of Acts was also historically reliable. According to the book of Acts, Peter, one of the inner circle of Jesus’ disciples, characterized Jesus as a prophet (Acts 3:11-26).
Assuming the historical reliability of the Gospels, it is very probable that Jesus claimed to be a prophet.
================
One more reason….
(vii) Like many of the O.T. prophets, Jesus called his people to repent:

• Mark 1:14-15
• Mark 6:7-13
• Matthew 4:12-17
• Matthew 11:20-24
• Matthew 12:40-42
• Luke 5:31-32
• Luke 10:12-14
• Luke 11:31-32
• Luke 13:1-5

## bookmark_borderJesus: True Prophet or False Prophet? – Part 1

In his book The Resurrection of God Incarnate, Richard Swinburne argues that the case for the resurrection of Jesus must include three major components:
I. General Background Evidence – evidence for and against the existence of God, and evidence about whether and why God would be likely to perform a miracle, especially raising someone from the dead.
II. Prior Historical Evidence – evidence for or against claims that Jesus had certain characteristics, characteristics which based on the purposes and motivations of God would make it likely that God would raise Jesus from the dead.
III. Posterior Historical Evidence – evidence for or against historical claims directly about the resurrection of Jesus:  (DOC) Jesus died on the cross the same day he was crucified.  (JAW) Jesus was alive and walking around about 48 hours after he was crucified.
I think Swinburne is correct to emphasize (I) and (II) as important and essential components of any reasonable case for the resurrection, but I also believe that Christian apologists will fail to produce solid evidence concerning components (I) and (II), in addition to their past failure to produce solid evidence in terms of component (III).
One big problem for Christian apologists concerning Prior Historical Evidence, is that there are good reasons to believe the following claim about Jesus:
(JFP)  Jesus was a false prophet.
If (JFP) can be shown to be true (or to be probably true), then it can be used in a powerful argument against the resurrection of Jesus:
(1) Jesus was a false prophet.
(2)  If Jesus was a false prophet, then it is very unlikely that God raised Jesus from the dead.
Therefore:
(3) It is very unlikely that God raised Jesus from the dead.
From my point of view it seems quite clear that Jesus was a false prophet, based on the evidence of the Gospels.  The Gospels do claim that Jesus died on the cross on the same day he was crucified (DOC), and they do claim that Jesus was alive and walking around about 48 hours after Jesus was crucified (JAW).  However,  the Gospels also provide plenty of evidence that Jesus was a false prophet.
So, if we accept the Gospels as providing evidence in terms of the Posterior Historical Evidence component of the case for the resurrection, then we must also accept the Gospels as providing evidence in terms of the Prior Historical Evidence component of that case.  It would be logically inconsistent and involve the fallacy of special pleading to accept the Gospel accounts as evidence for (DOC) and for (JAW), but reject the Gospel evidence that supports (JFP).
One could, of course, avoid the conclusion (JFP) by rejecting the Gospel accounts as fictional or as historically unreliable accounts, but then one would have to also reject the Gospel evidence put forward in support of (DOC) and (JAW).  One must either reject the historical reliability of the Gospels and reject most of the Posterior Historical Evidence for the resurrection, or else accept the historical reliability of the Gospels and accept a great deal of Prior Historical Evidence for the view that Jesus was a false prophet.  Either way, the case for the resurrection of Jesus fails (i.e. the case for the claim that “God raised Jesus from the dead” fails).
Before I get into an examination of the evidence for (1), which is the obvious point of contention between myself and Christian believers, let’s briefly consider the uncontroversial premise (2).  Why would it be very unlikely that God would raise Jesus from the dead if Jesus was a false prophet?  First, we must answer the question: What is a “false prophet”?
Most simply, a “false prophet” is someone who claims to be a prophet, who is NOT actually a prophet.   A prophet is someone who receives messages from God and who passes those messages on to others, especially to a group audience, or to the public in general.
I am not a prophet, but that does not make me a “false prophet”, because I don’t claim to be any sort of prophet.  I don’t claim to have received any messages from God, nor do I proclaim to others any messages that are supposedly messages from God.  Since I don’t claim to be a prophet and don’t claim to provide others with messages from God, I’m not a “false prophet”.
One sort of false prophet is basically a con artist, a deceiver.  Such a person does not believe he or she has received messages from God, but lies to others claiming to have received messages from God, and then provides made-up messages to others, especially groups of other people, either to obtain fame or admiration or money or favors from other people.
Another sort of false prophet is a delusional person who honestly believes that he or she has received messages from God, but in fact is either just mentally imbalanced (hearing voices in his or her head) or is receiving messages from some person other than God (from a hypnotist, from a telepathic psychic, from the spirit of a dead person, from a demon,  from a demi-god, etc.).  Such a person is not lying to others when claiming to have received messages from God, but those messages are NOT in fact from God, and thus such a person is NOT actually a prophet.
First, according to the Gospels, Jesus claimed to be a prophet:
Matthew 13:56-58 (NRSV)
56 And are not all his sisters with us? Where then did this man get all this?”
57 And they took offense at him. But Jesus said to them, “Prophets are not without honor except in their own country and in their own house.”
58 And he did not do many deeds of power there, because of their unbelief.
Mark 6:3-5  (NRSV)
3 Is not this the carpenter, the son of Mary and brother of James and Joses and Judas and Simon, and are not his sisters here with us?” And they took offense at him.
4 Then Jesus said to them, “Prophets are not without honor, except in their hometown, and among their own kin, and in their own house.”
5 And he could do no deed of power there, except that he laid his hands on a few sick people and cured them.
Luke 4:23-25 (NRSV)
23 He said to them, “Doubtless you will quote to me this proverb, ‘Doctor, cure yourself!’ And you will say, ‘Do here also in your hometown the things that we have heard you did at Capernaum.’”
24 And he said, “Truly I tell you, no prophet is accepted in the prophet’s hometown.
25 But the truth is, there were many widows in Israel in the time of Elijah, when the heaven was shut up three years and six months, and there was a severe famine over all the land;
Luke 13:32-34 (NRSV)
32 He said to them, “Go and tell that fox for me, ‘Listen, I am casting out demons and performing cures today and tomorrow, and on the third day I finish my work.
33 Yet today, tomorrow, and the next day I must be on my way, because it is impossible for a prophet to be killed outside of Jerusalem.’
34 Jerusalem, Jerusalem, the city that kills the prophets and stones those who are sent to it! How often have I desired to gather your children together as a hen gathers her brood under her wings, and you were not willing!
If a false prophet were to be executed or killed, why would it be very unlikely that God would raise such a person from the dead?  Some false prophets are con artists or deceivers, and it would obviously be a bad thing for God to raise a lying con artist from the dead.  That would involve God in a great deception.  But God is, by definition, a perfectly morally good person, and such a person would clearly NOT become involved in a great deception.
But what about false prophets who are sincerely mistaken?  They believe that they are receiving messages from God, and that they are passing those messages from God to others in accordance with God’s will, but they are mentally imbalanced or deceived or at least mistaken, and in fact are not receiving messages from God.  Should God raise such a false prophet from the dead?
Again, although the intentions of this sort of false prophet are good intentions, the effect on others is much the same.   Purely human messages are being represented to other people as if those messages were from God.  If God were to raise such a prophet from the dead, then God would be validating the teachings and messages of the false prophet as being messages from God, when those messages were NOT from God.  This would be a great deception, even though the intentions of such a false prophet are good intentions.  So, God would clearly not become involved in such a deception of others by raising such a false prophet from the dead.
But Jesus was NOT a prophet.  Jesus did not receive messages from God and pass those messages on to others.  Since Jesus claimed to be a prophet, but was NOT a prophet, it follows that Jesus was a false prophet.
The Gospels are full of evidence for the view that Jesus was NOT a prophet.    According to the Gospels, each of the following claims is true:
1. Jesus promoted worship of Jehovah.
2. Jesus promoted obedience to Jehovah.
3. Jesus promoted prayer to Jehovah.
4. Jesus promoted the belief that the Old Testament was inspired by God.
5. Jesus promoted the belief that Moses was a prophet.
6. Jesus promoted the belief that Isaiah was a prophet.
7. Jesus promoted the belief that Elijah was  a prophet.
8. Jesus promoted the belief that Jeremiah was a prophet.
9. Jesus promoted the belief that Jonah was a prophet.
10. Jesus promoted the belief that Daniel was a prophet.
11.  Jesus promoted the belief that his god planned to condemn many people to eternal suffering and misery for disobedience to his god’s commands.
12.  Jesus promoted the belief that his god planned to give an eternal life of happiness to some people and an eternity of suffering and misery to others based on whether people believed that Jesus was the divine Son of God.
But any of the above claims is sufficient to show that Jesus was a false prophet.  So, even if only one or two of these claims is correct, then Jesus was a false prophet.  If we assume (for the sake of argument) that the Gospel accounts are historically reliable, then each one of the above claims is probably true.  Each of the above claims would have a probability of about .8, assuming that the Gospels provide historically reliable information about the ministry and teachings of Jesus.
In general, the truth of one of the above claims would increase the probability of the other claims also being true.  For example, if it is true that Jesus promoted worship of Jehovah, then that makes it more likely that Jesus also promoted prayer to Jehovah and obedience to Jehovah.  If we knew that Jesus promoted the belief that Isaiah was a prophet, then it is more likely that Jesus also promoted the belief that Moses was a prophet, and that Jeremiah was a prophet.  Similarly, if one of these claims was known to be false, that would decrease the probability of the truth of the other claims.  If Jesus did NOT promote worship of Jehovah, then that decreases the probability that Jesus promoted prayer to Jehovah and obedience to Jehovah.  So, there is no simple probability calculation possible here, because the probability of the truth of each claim depends on the truth of the other claims.
But given that each of the above claims has a probability of about .8 (on the assumption of the reliability of the Gospel accounts), the probability that at least one of these claims is true is very high, significantly higher than .8.  Let’s be very conservative and estimate the probability that at least one of the above claims is true as being .9.  That means that the probability that Jesus was a false prophet is aproximately .9, assuming that each of the above claims would be sufficient to show that Jesus was a false prophet.
Of course, none of the above claims logically entails that Jesus was a false prophet (JFP).  I must provide a line of argument showing for each of the above claims how it provides powerful evidence for (JFP).  If I can do this, that still will only yield some sort of probability that (JFP) is the case, given the truth of one of the above claims.  If I can show that (JFP) is highly probable (P = .9) given either the truth of claim (1) or the truth of (2) or the truth of (3) or…, then the overall probability will be .9 x .9 = .81 or about .8 that (JFP) is the case (assuming the reliability of the Gospel accounts).
Thus, either the Gospel accounts are NOT reliable, and thus the case for (DOC) and (JAW) will fail, or else the Gospel accounts ARE reliable and the case for (JFP) will succeed.  Either way, the case for the resurrection of Jesus fails.  Either way, Christian apologists will fail to show that “God raised Jesus from the dead” (GRJ).

## bookmark_borderSwinburne’s Argument from Religious Experience – Part 5

Here is a brief plot summary of the movie Harvey:
Due to his insistence that he has an invisible six-foot rabbit for a best friend, a whimsical middle-aged man is thought by his family to be insane – but he may be wiser than anyone knows.
James Stewart played Elwood P. Dowd, the “whimsical middle-aged man” who could apparently see and converse with Harvey, a six-foot rabbit who was invisible to others.  The obvious conclusion is that Elwood is mentally ill and that his experiences of the six-foot rabbit are hallucinations.  But the movie casts doubt on this obvious conclusion, suggesting that we consider questions like these:
Q1. Does Elwood actually perceive a six-foot tall talking rabbit (a “Pooka” – a mischievous spirit who takes the form of an animal and who can appear selectively to  certain people)?
Q2. Does Elwood have veridical Pooka experiences of the presence of Harvey?
Q3. Does Elwood know that Harvey is present?
These questions have an obvious similarity to the questions that we are thinking about concerning the presence of God, alleged experiences of the presence of God, the veridicality of TREs, and Swinburne’s Argument from Religious Experience (AFR).
Our next order of business is to look more closely at the key term “veridical” , especially in the phrases “veridical theistic religious experience” and “veridical generic theistic religious experience”.   Swinburne argues that there is a very strong relationship between the veridicality of one generic TRE and the veridicality of other generic TREs.  The correctness or incorrectness of his reasoning on this issue depend crucially, it seems to me, on what the term “veridicality” means.
It  stikes me that (Q3) might well shed significant light on (Q2), and also on our question about the meaning of the key term “veridical”. I believe that the concept of veridicality is similar to, and closely related to, the concept of knowledge.
The first thing that occurs to most people is the question of TRUTH.  Is it TRUE that Harvey is present when Elwood is having his Pooka experiences?  Elwood BELIEVES that Harvey is present, but we have doubts about this belief and are inclined to think Elwood is mistaken, and that there is no six-foot tall rabbit in the room, nor that there is a mischievous spirit who is taking the form of a six-foot tall rabbit.
We are strongly inclined to think Elwood’s BELIEF that Harvey is present is a FALSE belief.  Elwood, we might say, does NOT know that Harvey is present because although Elwood BELIEVES that Harvey is present, he is mistaken, and this is a FALSE belief. Not just any belief counts as knowledge; the belief in question must be TRUE to count as knowledge.  Elwood’s belief about Harvey being present is FALSE, so this belief does not count as knowledge.  We might further conclude that Elwood is having non-veridical Pooka experiences, because there is in fact no six-foot tall rabbit and no mischievous spirit present in the room  with Elwood.
Definition 1 of ‘knows that x is present’:
Person P knows that x is present IF AND ONLY IF
(a) P believes x is present,  and
(b) it is true that x is present.
Definition 1 of ‘veridical experience of the presence of x’:
Person P has a veridical experience of the presence of x IF AND ONLY IF
(a) P has an experience of its seeming (epistemically) to P that x is present, and
(b) it is true that x is present.
If you have any background in epistemology or some familiarity with Socrates, you know that the idea that knowledge amounts to “true belief” is an overly simple analysis of the concept of knowledge, and that this analysis is mistaken.  There is at least the need for one more necessary condition: justification.  One can have a true belief by accident or chance or dumb luck.  But if I have a belief that is true by accident or chance or dumb luck, such a belief, though true, does not constitute knowledge.
John says: “I am thinking of a number between one and ten; guess the number.”
I respond: “You are thinking of the number seven.”
John replies: “Yes, that was the number.  Wow, good guess!”
I say: “I knew that you were thinking of the number seven.”
John says, “No you didn’t.  You just made a lucky guess.”
If I continue to claim to have KNOWN the number that John was thinking of, then John will challenge me to explain HOW I could have known the number, and if I claim to be able to read his mind, John will probably demand further proof of this amazing ability, perhaps by thinking of a number between one and a thousand, and seeing if I can still correctly identify that number.  This disagreement about whether I KNOW the numbers that John is thinking about is predicated on the distinction between a “lucky guess” and knowledge.  For a belief to be knowledge it must have something more going for it than simply being true.  Traditionally, going back to Socrates, knowledge was understood to be Justified True Belief, a subset of true beliefs:
Definition 2 of ‘knows that x is present’:
Person P knows that x is present IF AND ONLY IF
(a) P believes x is present,  and
(b) it is true that x is present, and
(c) P’s belief that x is present is rationally justified.
Definition 2 of ‘veridical experience of the presence of x’:
Person P has a veridical experience of the presence of x IF AND ONLY IF
(a) P has an experience of its seeming (epistemically) to P that x is present, and
(b) it is true that x is present, and
(c) P’s experience of its seeming (epistemically) to P that x is present was caused by x’s being present.
Note how this second definition of ‘veridical experience of the presence of x’ is parallel to the second definition of ‘knows that x is present’.
Note also that this analysis of ‘veridical experience of the presence of x’ corresponds to Swinburne’s view of perception:
It seems to me, for reasons that others have given at length, that the causal theory of perception is correct–that S perceives x (believing that he is so doing) if and only if an experience of its seeming (epistemically) to S that x is present is caused by x‘s being present.  So S has an experience of God if and only if its seeming to him that God is present is in fact caused by God being present. (EOG, p.296)
I take it that Swinburne understands the phrase ‘S perceives x’ to be equivalent to the phrase ‘S has a veridical experience of x’ as contrasted with non-veridical experiences such as hallucinations.
If a ‘veridical experience of the presence of x’ has the above three necessary conditions that when combined form a sufficient condition, then one would think that the logic of veridicality would NOT be symetrical with the logic of non-veridicality.  An experience can be veridical only by satisfying all three necessary conditions above.  But an experience could be non-veridical in a variety of ways: by failing to satisfy the conditions (a) and (c), or by failing to satisfy conditions (b) and (c), or by failing to satisfy (c), or by failing to satisfy all three conditions.  There are many different ways for an experience to be non-veridical, but only one way for an experience to be veridical.
In the case of an ordinary physical object, it could be that the object is in fact present, but that the object is NOT the cause of it seeming (epistemically) to the subject that the object is present.  For example, there might in fact be a cat sitting on a couch across the room from me, but my experience of it seeming (epistemically) to me that there is a cat sitting on the couch across the room is CAUSED BY a hypnotist planting a suggestion in my mind about a cat sitting on a couch across the room from me.  The cause of my experience is the hypnotist and the suggestion made by the hypnotist that I “see” a cat sitting on the couch.  The actual presence of the cat on the couch is NOT the cause of it seeming (epistemically) to me that there is a cat on the couch.  In this case, my experience is non-veridical, and yet there really is a cat sitting on the couch across the room from me.  Why couldn’t there be non-veridical generic TREs even if God was actually present in the room with the subject?
According to Swinburne, IF God exists, then ALL generic TREs are veridical:
And so, if there is a God, any experience which seems to be of God [of the presence of God] will be genuine…”                  (EOG, p.320).
Swinburne apparently did not notice the skeptical implication of this conclusion, namely that IF there is just one non-veridical generic TRE, then God does NOT exist!  This means that an atheist or a skeptic need only show that there is one single instance of a generic TRE that is non-veridical and the existence of God would thus be disproved.  But this seems contrary to common sense.  With ordinary objects there are various different ways that an experience can fail to be veridical, and in some of those ways it can still be the case that the object that seemed (epistemically) to the subject to be present was in fact present, as in the above example of the cat being present in the room but it’s presence NOT being the cause of it seeming (epistemically) to the subject that a cat was present in the room.
God is different than a cat, according to Swinburne, because God, if God exists, is involved in every causal event that occurs in any time and any place (because God, by definition, is omnipotent and omniscient and eternal).  Thus, God is involved in the cause of every experience that ever occurs:
But, if there is a God, he is omnipresent and all causal processes operate only because he sustains them.  Hence any causal processes at all that bring about my experience will have God among their causes… (EOG, p.320)
But Swinburne, it seems to me, has made a hasty conclusion here, which may not hold up under closer examination.   From this premise…
(GAC) God is among the causes that bring about the experience of its seeming (epistemically) to P that God is present.
Swinburne has drawn the following inference, related to one necessary condition of having a veridical experience:
(GPC) God’s being present with P is the cause of its seeming (epistemically) to P that God is present.
There are many different ways in which one person might cause another person to have a particular experience.  Being present in the same place and at the same time with the other person is just ONE of MANY different ways that one person could cause another person to have an experience.  For example, the hypnotist that causes it to seem (epistemically) to me that there is a cat present in the room with me could do this over the phone, and thus not be present with me.  Furthermore, even if the hypnotist were present, it is not the presence of the hypnotist that causes my non-veridical experience of the cat; rather, it is the action of hypnotizing and of saying certain things to me that causes my  non-veridical experience of the cat.
Since there are many different ways that one person can cause another person to have a particular experience, and since being present with the other person is just one such way, it seems to me that we cannot logically infer (GPC) from (GAC).  The claim made in (GAC) is too general and vague to logically imply the more specific claim made by (GPC).
Since God is always present to everyone, if God exists, there must be some additional factor that determines whether a particular person will experience the presence of God at a particular time and a particular place.  If generic TREs are sometimes caused by God, this presumably requires that God choose or will this experience to occur to that particular person at that time and that place.  But if this is so, then it is NOT the case that it is merely God’s presence that caused the generic TRE to occur, anymore than it is the hypnotist’s presence that caused me to have a non-veridical experience of the cat.

## bookmark_borderSwinburne’s Argument from Religious Experience – Part 4

Although I have been considering the implications of the idea that the veridicality of a Theistic Religious Experience (TRE) is independent of the veridicality of other TREs, this is NOT the view of Swinburne.  In fact, Swinburne clearly holds the opposite view, the view that the veridicality of a TRE is dependent on the veridicality of other TREs.  I will get into the details of this shortly.
First, let me back up for a moment and provide a key definition.  Swinburne defines “religious experience” in Chapter 13 of The Existence of God (2nd edition, hereafter: EOG, where he presents his Argument from Religious Experience, hereafter: AFR):
For our present purposes it will be useful to define it [a ‘religious experience’] as an experience of God (either of his just being there, or of his saying or bringing about something) or of some other supernatural thing. (EOG, p.295)
Note the emphasis on TREs: “an experience of God”.  Swinburne does not limit religious experiences to experiences of God, since the definition also includes experiences “of some other supernatural thing”.  However, Swinburne immediately points out that his focus is on TREs, especially on one specific kind of TRE:
For most of the discussion I shall be concerned with experiences that seem to be simply of the presence of God and not with his seeming to tell the subject something specific or to do something specific. (EOG, p.296)
So not only is Swinburne’s argument focused on TREs, but it is focused on a specific subset of TREs, what I have referred to as “generic” TREs.
Statements of key points in his argument also focus on TREs:
…a religious experience apparently of God ought to be taken as veridical unless it can be shown on other grounds significantly more probable than not that God does not exist. (EOG, p.321)
One who has had a religious experience apparently of God has, by the Principle of Credulity, good reason for believing that there is a God… (EOG, p.325)
Swinburne’s definition of ‘religious experience’ has a flaw, if taken as it stands.  It is not clear that one can have “an experience of God” if there is no God.  Swinburne does not intend to beg the question about the existence of God, and in the context of  the opening of Chapter 13, it is fairly clear that what he had in mind is an experience in which is seems (epistemically) to the subject that God is present (or that God is communicating a message to the subject, or that God is performing some action).
Swinburne leaves open the possibiilty that it might seem (epistemically) to a person that God is present when in fact there is no God, and thus God was NOT present to that person.  In other words, one can have a TRE that is non-veridical.  Having a theistic religious experience does NOT imply or entail that God was present or that God exists.  It might be the case that all TREs are non-veridical, that all TREs are misleading experiences.  Therefore, the occurrence of TREs does not in and of itself logically imply that God exists.
Back to the issue of dependency between the veridicality of generic TREs.  One obvious point is that if just one single generic TRE is veridical, then that means that God was present at least on that particular occasion.  But since God is omniscient and omnipotent and eternal (by definition), if God was present on one occaision, then it follows logically that God is present at any and every place at any and every time.  If God exists at one moment, then God exists in all moments, for any person who exists for only a finite duration of time cannot be ‘God’.  Any person who can only influence events in one particular part of the universe cannot be ‘God’.    Any person who is only aware of events in a particular place or at a particular time cannot be ‘God’.  In short, if God was present at one moment of time in one particular location, then God exists.  If God exists, then God is present at all times and at all places.
Recall that Swinburne saves his presentation of AFR until after all other major considerations for and and against the existence of God have been covered (in his view).  He believes that other relevant evidence shows that the existence of God is somewhat probable, that theism has a probability somewhere between .4 and .5:
g: God exists
.4 < P(g) < .5
But Swinburne is clearly talking about a conditional probability, a probability that is based on the evidence in the premises of his previous arguments for and against God.  Let’s use a letter to represent this background evidence that was considered prior to examination of AFR:
k: [the background evidence of the premises of the inductive arguments for and against God previously presented by Swinburne]
Now we can represent the probability range more accurately:
.4 < P(g|k) < .5
Swinburne believes he has a bit of wiggle room here, because all that is required for the success of AFR, in his view, is that the prior probability of the existence of God be more than just ‘very improbable’.  I would interpret that to mean the following assumption is required for the success of AFR:
P(g|k) > .2
If AFR is as good as Swinburne thinks, then the evidence in the premises of this argument should bump up the probability significantly, to make the existence of God “more probable than not”:
e: Many people have had generic TREs which are not subject to special considerations that cast doubt on the veridicality of those TREs.
P(g| e & k) > .5
If we have before us a collection of clean (i.e. no special considerations apply) generic TREs, and if we could somehow determine that one TRE in this collection was in fact veridical, that would, by itself, make it certain that God exists.  From that point forward any further instances of TREs would need to be evaluated on the basis of a NEW prior probability of the existence of God.  This new information, that at least one TRE was veridical, would shift the prior probabililty of the existence of God from somwhere between .4 and .5, all the way up to the maximum probabilty: 1.0.  In other words, as soon as one single TRE has been determined to be veridical, we have good reason to be much less skeptical about the veridicality of other TREs.
This is kind of like the idea of a miracle.  As soon as one single miracle has been determined to be valid, that establishes both the existence of God and the fact that God is, at least on some occasions, willing to intervene in nature for the sake of some human (or some animal) and to cause a violation of a law of nature.  Once one single miracle has been determined to be valid, then we would have good reason to be much less skeptical about other miracles.
A similar sort of relationship appears to hold in the case that we determine a particular TRE to be non-veridical.  If someone claims to have had an experience of the presence of God, but we determine that God was NOT present on that occasion, then we have also determined that God does NOT exist.  For if God DID exist, then God would have been present in the time and place that the person who claims to have experienced God had this experience that seemed to him/her to be an experience of the presence of God.  If God exists, then God exists at all times and at all places.
Furthermore, according to Swinburne, if God exists, then God is involved in the causation of any religious experience that seems (to the subject) to be an experience of God:
But, if there is a God, he is omnipresent and all causal processes operate only because he sustains them.  Hence any causal processes at all that bring about my experience will have God among their causes; and any experience of him will be of him as present at a place where he is.  And so, if there is a God, any experience that seems to be of God, will be genuine–will be of God. (EOG, p.320)
It appears that if there is just one single TRE that we determine was non-veridical, then we have determined that God does NOT exist, and that all other TREs are also non-veridical.  If God exists, then all TREs are veridical.  Therefore, if just one TRE is non-veridical, then God does NOT exist.
So, at least at first blush, it appears that if one single generic TRE is determined to be veridical, that shows that God exists, and that other generic TREs are also veridical, and it appears that if one single generic TRE is determined to be non-veridical, that shows God does NOT exist, and that other generic TREs must also be non-veridical.  Given these two sorts of logical dependencies, the probability tree diagram for generic TREs would look like this:

As soon as the status of the first TRE is determined, so is the status for any other TREs.  If the first TRE was veridical, then God exists, and all other TREs must then also be veridical, based on Swinburne’s views about the implications of the veridicality of a TRE.  If the first TRE is non-veridical, then all other TREs must then also be non-veridical.  Assuming that the prior probability of God’s existence is .4, we must either determine that the first TRE is veridical and raise that probabilty to 1.0, or determine that the first TRE is non-veridical and lower that probability to 0.
I don’t think Swinburne was aware of this implication of his view of the implications of determining a TRE to be veridical:
There are large numbers of people both today and in the past who have had religious experiences apparently of the presence of God and that must make it significantly more probable that any one person’s experience is veridical. (EOG, p.323-324)
It seems to me that the occurrence of large numbers of “religious experiences apparently of the presence of God” does NOT help the case for God.  The probability of the veridicality  of the first TRE that we consider will depend on the prior probability of the existence of God, but once the veridicality of that TRE is determined, the question of the existence of God will be answered, and no further TREs need be considered, because the veridicality of the remaining TREs will be determined by whether the first TRE was veridical or not, given Swinburne’s assumption that IF God exists, then ALL  generic TREs must be veridical.

## bookmark_borderSwinburne’s Argument from Religious Experience – Part 3

Previously, I have only considered the very simple case where one person has a memory of having previously had a theistic religious experience (hereafter: TRE) of a generic sort–an experience in which it seemed (epistemically) to him/her that God was present.  There were a couple of basic points made about probable inferences in contrast to necessary or deductive inferences, but there are even more interesting points of logic and probability ahead as we consider more complex and more realistic scenarios.
For most skeptics, we don’t have religous experiences, and if and when we do have something that might be called a religious experience, we are not inclined to believe that the experience was caused by God or by any sort of supernatural person or being.  This might also be true for many Christians and Jews and Muslims.  In any case, there is a significant portion of the population for whom the evidence of religious experience must be second-hand and based on the testimony of others.
Recall that Swinburne proposes a principle concerning testimony which is similar to his principles about experience and memory:

TESTIMONY

…(in the absence of special considerations) the experiences of others are (probably) as they report them. (EOG, p.322)

So for many of us, especially for us skeptics, doubters, and atheists, there is a longer chain of probable inferences requried to come to a conclusion about the existence of God.  Furthermore, since testimony about TREs is not a constant feature of our experiences, once such a testimony is given and heard, the force of that testimony remains only by means of memories of having heard (or read) that testimony.  Thus, for many people, and probably for most skeptics, there are number of steps of probable inferences in reasoning to  a conclusion about the probability of God on the basis of an alleged TRE:

1. It seems (epistemically) to me that I heard John testify last Sunday to having had a generic TRE when he was hiking in Yosemite last summer.

2. There are no special considerations casting doubt on my apparent memory about John testifying about having had a TRE.

3. If it seems to a subject that in the past he perceived something  or did something, then (in the absence of special considerations), probably he did. [Swinburne’s principle concerning memory]

Therefore:

4. It is probably the case that John testified last Sunday to having had a generic TRE when he was hiking in Yosemite last summer.

5. There are no special considerations casting doubt on John’s honesty and integrity.

6. If someone testifies to having had a certain experience on a certain occasion in the past, and if there are no special considerations casting doubt on that person’s honesty and integrity, then it is probably the case that it seemed (epistemically) to that person during his/her testimony that he/she had that experience on that occasion in the past. [This is an additional principle in the spirit of Swinburne’s other principles]

Therefore:

7.  It is somewhat probable (it is probable that it is probable) that at the time John was giving his testimony it seemed (epistemically) to John that he had had a generic TRE when he was hiking in Yosemite last summer.

8.  There are no special considerations casting doubt on the veridicality or reliability of John’s apparent memory about a religious experience while he was hiking in Yosemite last summer.

9. If it seems to a subject that in the past he perceived something  or did something, then (in the absence of special considerations), probably he did. [Swinburne’s principle concerning memory]

Therefore:

10.  It is probable that it is probable that it is probable that John had a generic TRE when he was hiking in Yosemite last summer.

11. There are no special considerations casting doubt on the veridicality or reliability of this generic TRE had by John.

12. In the absence of special considerations casting doubt on the veridicality or reliabilty  of the experience, if it seems (epistemically) to a subject that x is present (and has some characteristic), then probably x is present (and has that characteristic). [Swinburne’s principle of experience]

Therefore:

13. It is probable that it is probable that it is probable that it is probable that God was present with John during his generic TRE when he was hiking in Yosemite last summer.

Because a chain consisting of a number of probable inferences is required to get from that actual data (my apparent memory of John giving testimony) to the conclusion (about God being present with John during a religious experience), the probability is somewhat diminished.  Suppose that we interpret “probable” to mean having a probability of about .6.   In that case the chain of four probable inferences requires that we multiply this probability four times:

.6 x .6 x .6 x .6

= .36 x .36

= .1296

If we round this to a single significant figure, then the probability of God’s existence, based on this specific evidence and Swinburne’s principles, would be: .1  or one chance in ten.  Not a very impressive conclusion.

Furthermore, we are assuming that the premises that state there are no special considerations casting doubt (on the testimony, or memory, or experience) are certain.  But we are finite and fallible human beings, so those premises might add more uncertainty into the equation, and reduce the probability further.  And we also may be less than certain about the various epistemological principles, so that could further reduce the probability of the conclusion.

However, if we make the simplifying assumption that the veridicality of each generic theistic religious experience is independent of the veridicality of other generic theistic religious experiences, then because there is a great deal of testimony about a great many alleged generic theistic religious experiences, even a very modest probability of veridicality will be sufficient to show that it is virtually certain that God exists.  If you roll two dice a hundred times, you are very likely to come up with a pair of sixes on one of the rolls, even though it is unlikely that you will get a pair of sixes on any specific given roll.  Similarly, if each and every generic theistic religious experience has some small but significant chance of being veridical, then if a hundred such experiences occur, it is virtually certain that at least one would be veridical (i.e. God would in fact be present with the experiencer).

Let’s set aside that issue of the chain of probable inferences involved in a memory of a testimony about a religious experience.  Let’s assume that we have some way to be confident that a number of generic theistic relgious experiences have occurred.  Let’s assume that with the examples we have collected there are no special considerations casting doubt on the veridicality of the experiences, and that the veridicality of each generic theistic religious experience was independent of the veridicality of other such experiences. Let’s assume, therefore, that each generic theistic religious experience has a probability of .6 of being veridical (meaning that God was actually present and being experienced by the believer).

[It is important to note here that Swinburne thinks that the veridicality of a generic TRE is NOT independent of the veridicality of other generic TREs.  Furthermore, I agree that the veridicality of a generic TRE is NOT independent of the veridicality of other generic TREs.  However, it is still worth considering the idea of them being independent, partly because this is a simplifying assumption making probability calculations simpler, but also just to be a bit clearer about the importance and implications of dependence relationships between TREs by means of contrast with the idea of TREs being independent of each other (in terms of veridicality).]

Consider the paralell scenario of fair tosses of a coin, where the probability of getting heads is .5 and the probability of tails is also .5.  If you do three fair tosses, what is the probability that at least one toss would come up heads?  We know that EITHER at least one toss will come up heads OR no toss will come up heads.  Those are the only two possibilities.  So, it is certain that one or the other of those possibilities will be realized if we toss the coin three times:

O: At least one toss comes up heads.

N: No toss comes up heads.

E: Every toss comes up tails.

====================

15. Either O or N.    [This is an analytic truth; we know with certainty that this statement is true.]

16. A statement that is known with certainty to be true has a probability of 1.0.

Therefore:

17. P(O or N) =  1.0   [The probability that either O or N will occur EQUALS 1.0, i.e. this is certain.]

18. The probability of a disjunction is equal to the sum of the probabilities of each disjunct minus the probability of both disjuncts being true.

Therefore:

19. P(O) + P(N) – P(O and N) = 1.0    [The probability that O occurs PLUS the probability that N occurs MINUS the probability that both O and N occur EQUALS 1.0.]

20. If O occurs, then N does not occur, AND if N occurs, then O does not occur.  [O and N are mutually exclusive outcomes.]

Therefore:

21. ~(O and N)   [O and N are mutually exclusive outcomes, so we know with certainty that they cannot both occur.]

22. If we know with certainty that a statement is NOT the case, then the probability of that statement is zero.

Therefore:

23. P(O and N) = 0   [The probability that both O occurs and N occurs EQUALS zero.]

24.  If  two expressions are equivalent, then we can replace one expression with the other in any equation.

Therefore:

25. P(O) + P(N) – 0 = 1.0   [The probabilty that O occurs PLUS the probability that N occurs MINUS 0 EQUALS 1.0.]

26. x – 0 = x   [Any number minus zero equals that number.]

Therefore:

27:  P(N) – 0 = P(N)

Therefore:

28.  P(N) can be substituted in any equation for the expression P(N) – 0.

Therefore:

29. P(O) + P(N) = 1.0

30.  We can subtract the same thing from both sides of a true equation to produce a true equation.

Therefore:

31. P(O) = 1.0 –  P(N)   [The probability that O occurs EQUALS  1.0 MINUS the probability that N occurs.]

32. P(N) = P(E)   [The probability that no toss comes up heads is the same as the probability that every toss comes up tails.]

33. If they are equal, then we can substitute P(E) for P(N) in any true equation to produce another true equation.

Therefore:

34. P(O) = 1.0 – P(E)    [The probability that O occurs EQUALS 1.0 MINUS the probabilty that E occurs.]

That is a lot of work for this meager conclusion:

The probability that at least one toss comes up heads EQUALS 1.0 MINUS the probability that every toss comes up tails.

But it is easy to figure out the probability that every toss comes up tails.  Let’s start with the scenario where we do three (fair) coin tosses:

In order to come up with tails on all three tosses, one must come up with tails on the first toss (probability = .5) and then come up with tails on the second toss (probability = .5) and then come up with tails on the third toss (probability = .5).  So, the probability of coming up with tails on all three tosses is:

.5 x .5 x .5

= .25 x .5

= .125

P(E) = .125   (or .1 rounded to one significant figure).

We have determined that the probability of coming up with heads at least once is equal to 1.0 MINUS the probability of coming up tails on all three tosses:

P(O) =  1.0 – P(E)

Therefore:

P(O) = 1.0 – .125

Therefore:

P(O) = .875  (or .9 rounded to one significant figure)

So, it is very probable that in three (fair) tosses of a coin, that heads will come up at least one time.

What if we do six (fair) tosses of a coin?  What is the probability that heads will come up at least once?  The same logic applies.  The probability that heads will come up at least once EQUALS 1.0 MINUS the probability that tails will come up on every toss:

P(O) = 1.0 – P(E)

The only significant difference is that it is much less likely for tails to come up six times in a row, as compared with tails coming up three times in a row.  In order to come up with tails on all six tosses, the first toss must come up tails (probability = .5), the second toss must also come up tails (probability = .5), etc.  Thus the probability that tails will come up every time in six (fair) tosses of a coin is:

.5 x .5 x .5 x .5 x .5 x .5

=  .25 x .25 x .25

= .015625  [I will round off when calculation is completed.]

Therefore (in the case of six fair tosses):

P(O) = 1.0 – .015625

P(O) = .984375  (rounded to two significant figures: .98 , and rounded to one significant figure: 1)

We can see that with just six tosses of a coin it become highly probable, nearly certain, that at least one toss will come up heads.  We can reasonably conclude that the probability of heads coming up at least once in six fair tosses of a coin is greater than .9 but  less than 1.0:

.9 < P(O) < 1.0

The same logic and similar math applies to analogous scenarios with TREs, where we consider having evidence consisting of a set of three TREs and then consider having evidence consisting of a set of six TREs, given the simplifying assumption that the veridicality of a TRE is independent of the veridicality of other TREs.

Let’s re-define the basic statements abbreviated by the letters used in reasoning about coin tosses:

O:  At least one of the TREs is veridical (i.e. is the result of God actually being present).

N: None of the TREs is veridical.

E:  Every one of the TREs is non-veridical.

Suppose we have accepted three generic TREs as having no special considerations casting doubt on their reliability or veridicality.  Suppose that we take each one of the TREs to be probably veridical, meaning that there is a probability of .6 that the TRE is veridical.  Suppose we assume that the veridicality of any one TRE is independent of the veridicality of the other TREs.  We can represent this with a probability tree diagram that is very similar to the above tree diagram for coin tosses:

In this case we can apply the previous formula:

P(O) =  1.0 – P(E)

First, let’s determine the value of P(E), the probability that every one of the three TREs is non-veridical.  In order for all three of a series of three TREs to be non-verdical, the first TRE must be non-veridical (probability = .4, because the probabiliy of it being veridical is .6), and then the second TRE must also be non-veridical (probability = .4), and the third TRE must be non-veridical (probability = .4).  Thus, the probability that all three TREs in the series will be non-veridical is:

.4 x .4 x .4

= .16 x .4

= .064  [I will round after calculation is completed]

Therefore:

P(E) = .064

Therefore:

P(O) =  1.0 – .064

P(O) = .936  (or rounded to one signigicant figure: .9)

Thus, with just three “clean” (having no special considerations casting doubt on them)  generic TREs as evidence, the probability that at least one of them is veridical (i.e. is the result of God actually being present) is high, about .9.

What if we had six clean generic TREs as our evidence?  The probability that EVERY one of the six TREs was non-veridical would be this:

.4 x .4 x .4 x .4 x .4 x .4

= .16 x .16 x .16

= .004096  [I will round number when calculation is completed.]

Therefore:

P(E) = .004096

P(O) = 1.0 – P(E)

Therefore:

P(O) = 1.0 – .004096

P(O) = .995904  ( or approximately: 1.0)

With just six clean generic TREs, the probability (based on the various assumptions above) that at least one of these TREs was veridical (i.e. the result of God actually being present during the experience) would be about .99, nearly 1.0,  nearly certain.

To be continued…

## bookmark_borderSwinburne’s Argument from Religious Experience – Part 2

Richard Swinburne’s argument from religious experience (AFR) as given in The Existence of God (2nd ed.- hereafter: EOG) is based on three key epistemological  principles:

EXPERIENCE

…(in the absence of special considerations), if it seems (epistemically) to a subject that x is present (and has some characteristic), then probably x is present (and has that characteristic)… (EOG, p. 303)

MEMORY

If it seems to a subject that in the past he perceived something  or did something, then (in the absence of special considerations), probably he did. (EOG, p.303)

TESTIMONY

…(in the absence of special considerations) the experiences of others are (probably) as they report them. (EOG, p.322)

There are some interesting issues and complexities involving probability calculations that I have run into recently in thinking about this argument.  Let’s start simple, and then work towards more complicated and realistic scenarios. The simple scenario  I have in mind is this:

Just one person has just one religious experience of a generic theistic sort (i.e. this person has an experience which seems (epistemicallly) to him or her to be an experience of the presence of God).
What is the evidential force of this experience for that person who has the experience, given Swinburne’s principles?
If the person in question is having this religious exprience right now, then he or she does not need to make any assumptions about the reliability of his or her memory, nor is there a need to make use of testimony about the religious experiences of others, since we are assuming that there is just one religious experience on just this one occasion.  The reasoning of this person would go like this, based on Swinburne’s principle concerning experiences:
1. I am now having an experience in which it seems (epistemically) to me that God is present here and now.
2. There are no special considerations that cast doubt on the veridicality or reliability of this experience.
3. In the absence of special considerations that cast doubt on the veridicality or reliability of this experience, if it seems (epistemically) to a subject that x is present (and has some characteristic), then probably x is present (and has that characteristic).
Therefore:
4. It is probably the case that God is present here and now.
One obvious “special consideration” against the veridicality of this religious experience is evidence against the existence of God.  Swinburne recognizes that this is relevant, and he has saved the argument from religious experience for the end of his case for God.  So, he thinks that he has already dealt with various reasons and arguments against the existence of God, including the problem of evil, and thinks he has shown that there is at least a significant probability that God exists, even taking negative evidence into account.   I interpret him to claim that the probability for the existence of God is between about .4 and .5 prior to consideration of AFR.
But Swinburne thinks that he only needs to show that the probability of God’s existence is something greater than “very low” prior to consideration of religious experience.  I interpret that to mean that he only needs to show that there is a probability of at least .2 (two chances in ten) that God exists, prior to consideration of AFR.
I’m not going to directly challenge the above reasoning that is based on a single instance of a theistic religious experience.  I’m more interested in looking at the issues that arise in more complicated scenarios.
One obvious complication is that religious experiences usually only last for a few seconds or a few minutes.  This means that the above reasoning will only be of temporary relevance to the person who had the religious experience.  Once the experience is gone, the person who had the experience must rely on a MEMORY of the experience to justify his or her current belief in God:
5. It seems (epistemically) to me that last Friday night, I had an experience which (at that time) seemed (epistemically) to me to be an experience of the presence of God.
6. There are no special considerations that cast doubt on the  veridicality or reliability of my apparent memory of having had this experience last Friday night.
7. If it seems (epistemically) to a subject that he or she had a certain experience at a particular time in the past, then (in the absence of special considerations that cast doubt on the veridicality or reliability of that apparent memory) he or she probably did have that experience at that particular time in the past.
Therefore:
8.  It is probably the case that last Friday night I had an experience which (at that time) seemed (epistemically) to me to be an experience of the presence of God.
The apparent memory does NOT absolutely guarantee that the experience really happened as one thinks it happened.  An apparent memory can only make it very probable that the experience happened and was of a certain character.  Furthermore, even at the very moment that the religious experience was occurring, the experience did not absolutely guarantee that God was in fact present; it only made the presence of God probable.  In remembering a religious experience, one makes two probable inferences.  The first probable inference is from the apparent memory to the occurrence of the religious experience, and the second probable inference is from the occurrence of the religious experience to the existence of God.  Each probable inference in a chain of inferences lowers the probability of the conclusion.
At the time I was having the religious experience, I could be very confident that I was having an experience which seemed (epistemically) to me to be an experience of the presence of God.  So, at that time we could say that I was justifiably certain that I was having such an experience.  The probability that I was having such an experience could be said to be 1.0 for me at that time.  But that time has come and gone, and I can no longer be certain that I had that religious experience and that it was of the described character.
Suppose that given the apparent memory of having had a religious experience (of the sort described above), and given the absence of special considerations that cast doubt on the reliability of the apparent memory, the probable inference to the conclusion that the religious experience really occurred gives that conclusion a probability of .8.   That I am right now having an apparent memory of this event is something I can know with a very high degree of certainty, so let’s just say that the occurrence of the apparent memory is certain, that it has a probability of 1.0.  In this case, the conclusion that I had the religious experience (as described) last Friday night would be .8, based on the apparent memory of having had that experience.
If it were certain that I had an experience that seemed (epistemically) to me to be an experience of the presence of God, this would NOT make it certain that God exists, but if there are no special considerations that cast doubt on the veridicality or reliability of that expereince, then, according to Swinburne, I can justifiably infer that it is probable that the experience was veridical and thus that God probably exists.  Let’s suppose that given that it was certain that I had a religious experience of the sort described, this would make the probability of the  existence of God .8.  It is tempting at this point to reason along the lines of a hypothetical syllogism:
9. If someone has an apparent memory of a religious experience of the presence of God (and there are no special considerations casting doubt on the memory), then that person probably did have a religious experience of the presence of God.
10.  If someone had a religious experience of the presence of God (and there are no special considerations casting doubt on that experience), then that person  probably was in fact in the presence of God and God probably does exist.
Therefore:
11.  If someone has an apparent memory of a religious experience of the presence of God (and there are no special considerations casting doubt on that memory, and there are no special considerations casting doubt on the experience), then that person probably was in the presence of God and God probably does exist.
From (11) we can form an argument for the probability that God exists, by adding a few premises:
12.  I have an apparent memory of a religious experience of the presence of God.
13.  There are no special considerations casting doubt on that apparent memory.
14. There are no special considerations casting doubt on that religious experience.
Therefore:
15.  I probably was in the presence of God and God probably does exist.

However, there are a couple of problems with the logic of the argument for (11).  First of all, the following is NOT a valid deductive argument:
16. If P, then probably Q.
17. If Q, then probably R.
Therefore:
18. If P, then probably R.
The concusion does not follow logically, because in a chain of probable inferences, the probability is reduced at each step.  Suppose that the truth of P made the probability of Q  equal to .6.  In that case, premise (16) would be true (if we interpret “probably” to mean having a probability greater than .5).  Suppose that the truth of Q makes the probability of R equal to .6.  In that case, premise (17) would be true. The truth of P would thus only make Q somewhat probable (.6), so we would not be certain that Q was true, and thus we would not be certain that premise (17) applies. There is only a probability of .6 that Q is the case, so only a probability of .6 that premise (17) applies.  Only if Q turns out to be true will the logic of premise (17) be activated.  Thus, we must multiply the probabilities of the two probable inferences:  .6  x .6 =  .36.    So, if P is the case, then this argument only supports the conclusion that the probability of R would be .36 , or rounding to one digit: .4.  But a probability of .4 is too low to justify the conclusion that R is “probably” true.  In order to conclude that R is “probably” true, one would need to show that the probability of R was greater than .5 (at the least).
Another way to put this point, is to note that this relationship (If X, then probably Y) is NOT transitive, as opposed to the similar sounding relationship If X, then Y, which is transitive.  In a chain of many implications or entailments, the strength of the logical connection does not weaken:
19. If P, then Q.
20. If Q, then R.
21. If R, then S.
22. If S, then T.
Therefore:
23. If P, then T.
The above reasoning is deductively valid.  The logical connection between P and T in the conclusion is just as strong as the logical connection between P and Q in premise (19).   Swinburne is very much aware of this basic logical point that distinguishes probable inferences from implications or entailments.
There is another problem or complexity involved in this argument form:
16. If P, then probably Q.
17. If Q, then probably R.
Therefore:
18. If P, then probably R.
With inductive reasoning, the probability of a claim or belief can change with new or additional evidence.  Thus, although P might well make Q probale in most circumstances, there are possible circumstances in which although P is the case, Q would definitely be false.  For example, suppose that you see that I frequently drive a late-model Mercedes-Benz sedan.  You might reasonably infer that I am probably NOT poor. But if you learn that I have a part-time job as a driver for a wealthy business man, then your previous inference is cast into doubt.  I might well be poor, even though I frequently drive a late-model Mercedes-Benz sedan.  That is how inductive reasoning works.  New information can alter the probability of a claim or belief.
This means that in order for premises like (16) or (17) to be true, we must understand them to involve an unstated qualification: other things being equal.
16a. If P, then probably Q (other things being equal).
17a. If Q,then probably R (other things being equal).
Therefore:
18a. If P, then probably R (other things being equal).
In other words, probable inferences and inductive reasoning are always to be thought of as contextual, as referring to a certain collection of information or assumptions, and so there is always the possibility that new or additional information could alter the probabilities.
To be continued…

## bookmark_borderMatthew Ferguson: History, Probability, and Miracles (2013)

Historian Matthew Ferguson uses Bayes’ Theorem to analyze the historicity of miracle claims. Among other things, Ferguson compares the historical evidence for a purported miracle by Vespasian to the historical evidence for the purported resurrection of Jesus.
Note: as always, links do not constitute endorsement.

## bookmark_borderRepost: Brittany Maynard and the Problem of Evil

In case you’ve been under a rock (or you’re reading this in the future when it is an old, archived post), Brittany Maynard, a women with terminal brain cancer, died by assisted suicide last weekend in the U.S. state of Oregon, where it is legal.
Brittany’s life and death are an especially tragic combination of two or more aspects of the problem of evil.
First, the tragic nature of her story is an example of the evidence appealed to in the atheistic argument from triumph and tragedy. According to that argument, facts about the types and distribution of triumphs and tragedies are more probable on naturalism than on theism. The point here is not that (a) theism predicts the nonexistence of tragedies or (b) literally every human being suffers tragedies or enjoys triumphs. Rather, the focus of this argument is on the distribution of triumph and tragedy. Out of those people who do experience triumphs or tragedies, the number of people who experience tragedies is greater than the number of people who experience triumphs. Moreover, we know that the number of extreme tragedies (call them “horrific tragedies”) is much greater than the number of extreme triumphs (call them “glorious triumphs”).
Second, the gratuitous (and apparently morally random) biological pain caused by her condition if allowed to progress until death is more probable on naturalism than on theism (see: the atheistic argument from the biological role of pain and pleasure). Note: the problem is not the presence of physical pain and pleasure in general, since physical pain and pleasure can be (and often is) biologically useful. Rather, the problem is the fact that much pain and pleasure is biologically gratuitous (i.e., it does not contribute to the biological goals of survival or reproduction) and apparently morally random (i.e., much of it is not apparently connected to “greater goods” such as the exercise of free will). While it’s possible that God exists and has unknown moral reasons for allowing biologically gratuitous pain and pleasure, the fact that such pain and pleasure exists is not what we would have predicted “beforehand” on theism. In contrast, naturalism–combined with the background knowledge that human beings exist and are the products of unguided evolution–does predict this. So, all other evidence held equal, the biological role of pain and pleasure is very much more probable on naturalism than on theism.
Third, if Brittany did not feel God’s comforting presence during the end of her life — and I have no idea if she did or not — her story would also be an example of another atheistic argument at the intersection of arguments from evil and arguments from hiddenness: the argument from divine silence during tragedies.
Fourth, if there are religious groups which do support Euthanasia, then the argument from ethical confusion applies. In fact, if (a) there is sincere ethical disagreement among theists regarding Euthanasia and (b) if Euthanasia is not objectively morally wrong, then ethical disagreement becomes an additional, independent instance of the problem of evil for theists. We would then have a situation where, if theism were true, a perfectly loving God allowed theists who, in this hypothetical situation, wrongly believed Euthanasia was morally wrong and that belief contributed to Brittany’s suffering. And that state of affairs is more probable on naturalism than on theism. This last point (about suffering caused by moral condemnation) is not hypothetical. Before her death, Brittany spoke about the emotional toll the criticism of her choice took on her:

“When people criticize me for not waiting longer, or, you know, whatever they’ve decided is best for me, it hurts,” she says, “because really, I risk it every day, every day that I wake up.”

So Brittany’s tragic story exemplifies at least two, if not four, different arguments from evil for naturalism and against theism.
Sometimes theists object to these kinds of arguments on the basis that they focus on the “God of the philosophers,” rather than, say, Christian theism or Islamic (sp?) theism. This common yet confused objection reveals the objector’s misunderstanding of probability theory. Since Christian theism entails theism, it follows necessarily that the probability of Christian theism can be no greater than the probability of theism. (The two values may be equal or Christian theism may be less probable than theism.) We can state this point as a general principle: if A entails B, then it follows necessarily that Pr(A) <= Pr(B).

## bookmark_borderThe Carrier-Barnes Exchange on Fine-Tuning

Reader GGDFan77 asked me for my thoughts on the exchange between Dr. Richard Carrier, who I respect and consider a friend, and Dr. Luke Barnes regarding fine-tuning arguments. I initially responded in a series of comments in the combox for my post about Hugh Ross’s estimates for the probability of life-permitting prebiotic conditions. But those turned out to be so lengthy that I think the topic deserves its own dedicated post.
Here’s some brief context for readers not familiar with the exchanges between Dr. Richard Carrier and Dr. Luke Barnes:
* Dr. Carrier wrote an essay, “Neither Life Nor the Universe Appear Intelligently Designed,” in The End of Christianity (ed. John Loftus, Buffalo: Prometheus Books, 2011), pp. 279-304.
* Dr. Barnes wrote a four part series on his blog critiquing that essay by Carrier.
* Dr. Carrier and Dr. Barnes had an extensive back-and-forth exchange in the combox on Carrier’s blog.
Let me preface my comments by saying that I have a lot of empathy for any writer, including Dr. Carrier, who is trying to use the formal apparatus of Bayes’ theorem in a way that is accessible to a beginning-to-intermediate audience, which I take to be the target audience of The End of Christianity. If you go for too much precision and formalism, you risk losing your audience. If you focus too much on accessibility, you risk misunderstandings, oversimplifications, and outright errors. Finding the right balance isn’t easy.

## Part 1

With all due respect to Dr. Carrier, I find part 1 of Dr. Barnes’ critique to be very persuasive and, in fact, to be a prima facie devastating critique. (I quickly skimmed the combox on Dr. Carrier’s site to see if they debated anything relevant to part 1, but I didn’t find anything, so it appears that the points in part 1 of Dr. Barnes’ series have gone unchallenged by Dr. Carrier.)
In particular, I agree with the following points by Dr. Barnes.

• “Bayes’ theorem, as the name suggests, is a theorem, not an argument, and certainly not a definition.”
• “Also, Carrier seems to be saying that P(h|b), P(~h|b), P(e|h.b), and P(e|~h.b) are the premises from which one formally proves Bayes’ theorem. This fails to understand the difference between the derivation of a theorem and the terms in an equation.”
• “Crucial to this approach is the idea of a reference class – exactly what things should we group together as A-like? This is the Achilles heel of finite frequentism.”
• “It gets even worse if our reference class is too narrow.”
• “This is related to the ‘problem of the single case’. The restriction to known, actual events creates an obvious problem for the study of unique events.”
• “Carrier completely abandons finite frequentism when he comes to discuss the multiverse.”
• “Whatever interpretation of probability that Carrier is applying to the multiverse, it isn’t the same one that he applies to fine-tuning.”
• “If we are using Bayes’ theorem, the likelihood of each hypothesis is extremely relevant.”

• In his essay, Carrier writes: “Probability measures frequency (whether of things happening or of things being true).” Not exactly. The frequentist interpretation of probability measures relative frequency, but the frequentist interpretation of probability isn’t the only interpretation of probability. There are “many other games in town” besides that one; there is also the epistemic interpretation of probability (aka “subjective” aka “personal” aka “Bayesian”), which measures degree of belief. Thus, to say that probability just is relative frequency is to beg the question against all the rival interpretations of probability. (And, for the record, I’m actually a pluralist when it comes to probability; following Gillies, I think different interpretations can be used in different situations.)

## Part 2

Here are my thoughts on Part 2 of Dr. Barnes’ reply.

This simulation tells us nothing about how actual cars are produced.

I strongly agree.

The fact that we can imagine every possible arrangement of metal and plastic does not mean that every actual car is constructed merely at random.

I agree.

Note a few leaps that Carrier makes. He leaps from bits in a computer to actual universes that contain conscious observers. He leaps from simulating every possible universe to producing universes “merely at random”.

I agree.

This is a textbook example of affirming the consequent, a “training wheels” level logical fallacy.”

I think this is an uncharitable interpretation of Carrier’s statements by Barnes.

False. Obviously False.

I disagree with Barnes. Here is the passage by Carrier which Barnes is referring to.

It simply follows that if we exist and the universe is entirely a product of random chance (and not NID), then the probability that we would observe the kind of universe we do is 100 percent expected.

Let’s abbreviate the statement “we exist” as B (for our background knowledge); the statement “the universe is entirely a product of random chance (and not NID)” as C (for chance); and the statement “we observe the kind of universe we do” as E (for evidence). Then we can abbreviate the paragraph just quoted as:

Pr-L(E | B & C) = 1, where Pr-L represents a logical probability.

It seems to me that Carrier is correct. Contrary to what Barnes writes, however, it doesn’t follow that we can’t conclude it is highly probable someone was cheating in a game of poker. It just means that the correct way to show that cheating took place is not to use an argument analogous to the argument Carrier is refuting.
Aside: Reading the exchange between Carrier and Barnes reminds me of one of my wishes for people who use Bayes’ Theorem in this way: I really wish people would explicitly state the propositions they are including in their background knowledge. It avoids misunderstandings and misinterpretations.

Carrier says that “if the evidence looks exactly the same on either hypothesis, there is no logical sense in which we can say the evidence is more likely on either hypothesis”. Nope. Repeat after me: the probability of what is observed varies as a function of the hypothesis. That’s the whole point of Bayes theorem.”

I think Barnes is being uncharitable to Carrier. When Carrier writes, “the evidence looks the same,” I interpret him to mean “when the evidence is equally likely on either hypothesis.”

All that follows from the anthropic principle…

I need to study this section in detail, but I think agree with Barnes.
I would add the following. In his essay, Carrier writes this:

Would any of those conscious observers be right in concluding that their universe was intelligently designed to produce them? No. Not even one of them would be.

It would be most helpful if Carrier would explicitly defend this statement: “No. Not even one of them would be.” Unless I’ve misunderstood his argument, I think this is false. If we include in our background knowledge the fact that Carrier’s hypothetical conscious observers exist in a universe we know is the result of a random simulation, then we already know their universe is the result of a random simulation. Facts about the relative frequency aren’t even needed: we know the universe is the result of a random simulation.
If, however, we exclude that from our background knowledge, so that we are in the same epistemic situation as the hypothetical observers, then things are not so easy. Again, it would be helpful if Carrier could spell out his reasoning here.

## Part 3

Let’s move onto Part 3 of Barnes’s reply.

“Refuted by scientists again and again”. What, in the peer-reviewed scientific literature? I’ve published a review of the scientific literature, 200+ papers, and I can only think of a handful that oppose this conclusion, and piles and piles that support it.

I think Dr. Carrier absolutely has to respond to this point by Dr. Barnes or publicly issue a retraction.

With regards to the claim that “the fundamental constants and quantities of nature must fall into an incomprehensibly narrow life-permitting range”, the weight of the peer-reviewed scientific literature is overwhelmingly with Craig. (If you disagree, start citing papers).

This strikes me as a devastating reply. Like the last point, I think Dr. Carrier absolutely has to respond or else issue a retraction.

He can only get his “narrow range” by varying one single constant”. Wrong. The very thing that got this field started was physicists noting coincidences between a number of constants and the requirements of life. Only a handful of the 200+ scientific papers in this field vary only one variable. Read this.

Ouch. Same as the last two points.

“1 in 8 and 1 in 4: see Victor Stenger”. If Carrier is referring to Stenger’s program MonkeyGod, then he’s kidding himself.

I haven’t studied MonkeyGod enough to have an opinion, so I have no comment on this one.

In all the possible universes we have explored, we have found that a tiny fraction would permit the existence of intelligent life. There are other possible universes,that we haven’t explored. This is only relevant if we have some reason to believe that the trend we have observed until now will be miraculously reversed just beyond the horizon of what we have explored.

If I understand Dr. Barnes’ point correctly here, then I think he is making a simple appeal to induction by enumeration and I think his argument is logically correct.

In fact, by beginning in our universe, known to be life-permitting, we have biased our search in favour of finding life-permitting universes.

I find this point very interesting. I hadn’t even thought of it that way, but I think he’s right.

Nope. For a given possible universe, we specify the physics. So we know that there are no other constants and variables. A universe with other constants would be a different universe.

think I agree with this.

How does a historian come to think that he can crown a theory “the most popular going theory in cosmological physics today” without giving a reference? He has no authority on cosmology – no training, to expertise, no publications, and a growing pile of physics blunders.

Ouch.

In any case, the claim is wrong…

I don’t have the physics expertise to evaluate this paragraph.

By what criteria is that the simplest entity imaginable? If the point is lawless, why does it evolve into something else? How does it evolve? What evolves? What defines the state space? If it is a singular point, how are there now many spacetime points? Why are they arranged in a smooth manifold? Why spacetime? What if space and time aren’t fundamental? It’s not clear that a lawless physical state makes any sense. Even if it does, if it’s lawless, why do we observe a law-like universe?

Good questions.

Fine-tuning doesn’t claim that this universe has the maximum amount of life per unit volume (or baryon, or whatever). So this argument is irrelevant.

Dr. Barnes is, of course, correct that fine-tuning doesn’t logically entail that this universe has the maximum amount of life per unit volume, in the sense that “fine-tuning” is logically compatible with “the universe NOT having the maximum amount of life per unit volume.” But I disagree with Dr. Barnes that the hostility of life is irrelevant. In fact, as I’ve argued before, focusing only on facts about “fine-tuning” while ignoring facts about “course-tuning” (i.e., the hostility of the universe to life) commits the logical fallacy of understated evidence.

## Part 4

Let’s move onto part 4 of Dr. Barnes’ reply. Barnes writes:

What is Carrier’s main argument in response to fine-tuning, in his article “Neither Life nor the Universe Appear Intelligently Designed”? He kept accusing me of misrepresenting him, but never clarified his argument.

I agree.

Bayes’ theorem follows from Cox’s theorem, which assumes only some reasonable desiderata of reasoning.

I haven’t studied Cox’s theorem, so I can’t comment on that directly. Instead, I want to point out that Bayes’s theorem also follows from the Kolmogorov axioms of the probability calculus plus the definition of conditional probability.

A given proposition $K_i$ can play the role of “background” or “evidence”, depending on the term.

I agree.

Talking about “the prior” or “the likelihood” in such a context is ambiguous. Better to use notation.

I strongly agree.

Look closely at p(o | ~NID.b’). This is the probability that a universe with intelligent observers exists, given that there is no intelligent cause of their universe, and given background information b’ that does not imply o. This is exactly the probability that Carrier is afraid of, the one that could equal an “ungodly percentage” (pg. 293). It is the probability that “the universe we observe would exist by chance” (pg. 293). Carrier argues that this term is irrelevant because ignores o. It does, but rightly so. The posterior does not ignore o. Look at Bayes’ theorem: p(H|EB) = p(E|HB) p(H|B) /p(E|B).  Both E and B are known, and yet the likelihood p(E|HB) just ignores the fact that we know E! Rightly so! This is the whole point of Bayes’ theorem.

1. Here I think Dr. Barnes is being just a tad snarky (“This is exactly the probability that Carrier is afraid of”).
2. This may be a nitpick, but I wouldn’t word things the way Dr. Barnes does, when he writes that p(o | ~NID.b’) is “the probability that ‘the universe we observe would exist by chance.'” Instead, I would define that probability in plain English as “the probability that intelligent observers exist conditional upon our background knowledge conjoined with the hypothesis that a non-terrestrial intelligent designer did NOT design the universe.” The key difference here is that the latter phrasing keeps the distinction between “the universe we observe” and “intelligent observers exist.”
3. I strongly agree with this: “Carrier argues that this term is irrelevant because ignores o. It does, but rightly so. The posterior does not ignore o. Look at Bayes’ theorem: p(H|EB) = p(E|HB) p(H|B) /p(E|B).  Both E and B are known, and yet the likelihood p(E|HB) just ignores the fact that we know E! Rightly so! ”
4. Again, this may be another nitpick but I agree and disagree with this statement: “This is the whole point of Bayes’ theorem.” Not exactly; here I think Dr. Barnes is unwittingly presupposing the epistemic interpretation of Bayes’s theorem. Based on that interpretation, he’s correct. On rival interpretations–such as the frequency interpretation–we wouldn’t talk about knowledge at all, but the relative frequency among some reference class.

Here’s the problem with the argument above. What (3) shows is that, since f follows from o, I need not condition the posterior on f. There is a redundancy in our description of what we know. But that does not mean that the posterior p(NID|f.b) is independent of the “ungodly percentage” p(o | ~NID.b’). The surprising fact on ~NID, that a life-permitting universe universe exists at all, cannot hide in the background. We can draw it out. It’s right there in equation (7).

I agree. Dr. Barnes is making a very similar point to the one I make below, where I talk about pushing the problem back a step.

There a couple of different versions of NID floating around Carrier’s essay….

I agree with pretty much this entire section of Dr. Barnes’s essay.

Question 5: What mathematician should I read to learn about reference classes and why probabilities measure frequencies? Is Carrier a frequentist or a Bayesian?

Actually, this is a question not best suited for a mathematician, but a philosopher. In my opinion, the “go-to” reference books for this question are (1) Choice & Chance by Brian Skyrms and (2) Philosophical Interpretations of Probability by Gillies.

Question 9: Moving on to Carrier’s scientific claims, there’s some explaining to do.

I think Dr. Carrier must directly answer the questions in the bulleted list that follows.

This time could have been spent showing that I am wrong. More time is spent attacking me than defending, or even explaining, his case. Take the comment on January 7, 2014 at 8:43 am. Of 14 sentences: 1 clarification of a previous comment, 2 repetitions of points from his article that I agreed with, 2 claims contrary to mine (hurray! interaction!), and 9 that merely accuse of error and incompetence.

I strongly agree. I hope that Dr. Carrier will directly respond to Dr. Barnes without the personal attacks.

## Carrier’s Endnote 23

GGDFan777 also asked me to parse endnote 23 of Dr. Carrier’s essay. Unless otherwise indicated, the quotations are from that endnote.

This is undeniable: if only a finely tuned universe can produce life, then by defintion P(FINELY TUNED UNIVERSE | INTELLIGENT OBSERVERS EXIST) = 1, because of (a) the logical fact that “if and only if A, then B” entails “if B, then A” (hence (“if and only if a finely tuned universe, then intelligent observers” entails “if intelligent observers, then a finely tuned universe,” which is strict entailment, hence true regardless of how that fine-tuning came about; by analogy with “if and only if colors exist, then orange is a color” entails “if orange is a color, then colors exist”; note that this is not the fallacy of affirming the consequent because it properly derives from a biconditional), and because of (b) the fact in conditional probability that P(INTELLIGENT OBSERVERS EXIST)=1 (the probability that we are mistaken about intelligent observers existing is zero, a la Descartes, therefore the probability that they exist is 100 percent) and P(A and B) = P(A|B) x Pr(B), and 1 x 1 =1.

I agree.

Collins concedes that if we include in b “everything we know about the world, including our existence,” then P(L | ~God & A LIFE-BEARING UNIVERSE IS OBSERVED) = 100 percent (Collins, “The Teleological Argument,” 207).

I don’t have access to the material by Collins, but I don’t have any reason to doubt that what Carrier says here is correct.

He thus desperately needs to somehow “not count” such known facts. That’s irrational, and he ought to know it’s irrational.

Sigh. I think the statement “desperately needs” is snarky and off-putting. I think these two sentences are uncharitable to Collins, for reasons I will explain below.

He tries anyway (e.g., 241-44), by putting “a life-bearing universe is observed” (his LPU) in e instead of b. But then b still contains “observers exist,” which still entails “a life-bearing universe exists,” and anything entailed by a 100 percent probability has itself a probability of 100 percent (as proven above). In other words, since the probability of observing ~LPU if ~LPU is zero (since if ~LPU, observers won’t exist), it can never be the case that P(LPU|~God.b) < 100 percent as Collins claims (on 207), because if the probability of ~LPU is zero the probability of LPU is 1 (being the converse), and b contains “observers exist,” which entails the probability of ~LPU is zero.

I agree with his analysis, but — you knew there was a “but” coming — I think this misses the point, which seems to be a restatement of the anthropic principle dressed up in the formalism of probability notation. Yes, if we include “(embodied) intelligent observers exist” in our background knowledge (B), then it follows that a life-permitting universe (LPU) exists. But that isn’t very interesting. In one sense, this move simply pushes the problem back a step.
To see why, we can (in a sense) do a Bayesian analysis in reverse. Abstract away everything we know, including our own existence, and include in our background knowledge only the fact that our universe exists. Based on that fact alone, the prior (epistemic) probability of “(embodied) intelligent observers exist” is not 1 on naturalism and it is not 1 on theism.
In the jargon of academic philosophy of religion, the proponent of a fine-tuning argument for theism is asking us to compare the epistemic probability–not relative frequency–of a life-existing universe conditional upon theism to the epistemic probability of a life-existing universe conditional upon naturalism. To respond to that argument with “But we exist” misses the point.
The proponent of the fine-tuning argument can, should, and will respond, “No shit, Sherlock. Everyone agrees that we exist. The question is whether the life-permitting preconditions of our universe is evidence relevant to theism and naturalism.”

If (in even greater desperation) Collins tried putting “I think, therefore I am” in e, his conclusion would only be true for people who aren’t observers (since b then contains no observers), and since the probability of there being people who aren’t observers is zero, his calculation would be irrelevant

Again, I find the snark (“greater desperation”) off-putting, but let’s put that aside. At the risk of repeating myself, the fact that each of us knows that we exist doesn’t make fine-tuning arguments go away. Yes, we know that our universe is life-permitting because we know that we exist. But why is our universe life-permitting? Some philosophers (including both theists and atheists like Paul Draper) argue that that is evidence favoring theism over naturalism. If they are right, then so be it. But if they are wrong, they are NOT wrong because we exist. That objection just doesn’t work.

(it would be true only for people who don’t exist, i.e., any conclusion that is conditional on “there are no observers” is of no interest to observers).

Dr. Carrier doesn’t speak for all observers. I’m an observer and find the question of interest. So does Paul Draper. So do many atheist philosophers who don’t think fine-tuning arguments work, including Bradley Monton, Keith Parsons, Graham Oppy, Quentin Smith, and so forth. So do many (but not all) theist philosophers. So do many non-philosophers of all stripes. If he doesn’t find the question of interest, that’s fine. But, at risk of stating the obvious, his lack of interest in the argument isn’t a defeater for the argument.

## bookmark_borderHow Hugh Ross Calculates the Improbability of Life on Earth due to Chance Alone

As someone who knows a thing or two about probability, I’ve always wanted to dive into the technical details for how proponents of cosmic fine-tuning arguments justify the probability estimates associated with such arguments. Along those lines, I just found this page on Hugh Ross’s Reasons to Believe website:
Probability for Life on Earth (APR 2004)
Ross arrives at the conclusion that the probability of life on earth, conditional upon the hypothesis that it arose by chance alone, is 1 in 10282.
I may eventually write up my own thoughts on his calculations, but in the meantime consider this post an exercise for the reader. 🙂 What do you think?