THE DYNAMIC PROBABILITY OBJECTION

The dynamic probability objection to my reasoning about the resurrection is based on the general logic of Richard Swinburne’s case for the resurrection.  In his book The Existence of God,  Swinburne argues that various inductive arguments for God form a cumulative case that makes the existence of God “more probable than not.” (Existence of God, 2nd ed., p.342).  In Swinburne’s book The Resurrection of God Incarnate, he begins with the assumption that the existence of God is as probable as not, and ends up concluding that the claim God raised Jesus from the dead is very probable, which means that he ends up concluding that the existence of God is very probable:

My conclusion is that, given that general background evidence makes it at least as likely as not that there is a God, when we add the detailed historical evidence, the total evidence makes it probable that there is indeed a God who became incarnate in Jesus Christ and rose from the dead on the first Easter morning.   (The Resurrection of God Incarnate, p. 5)

If the background evidence leaves it not too improbable that there is a God likely to act in the ways discussed, then the total evidence [including relevant historical evidence about the life and death of Jesus] makes it very probable that Jesus was God incarnate who rose from the dead.     (The Resurrection of God Incarnate, p.203)

It is important to note that the probability of the existence of God is dynamic in the logic of Swinburne’s thinking about the resurrection.

First, before considering various inductive arguments for and against God, the probability of God’s existence is very low, but not zero. Swinburne does not specify an estimated probability for the existence of God prior to consideration of any empirical evidence, but a reasonable guess is that he would put this probability at between .001 and .01.

Second, after considering various inductive arguments for and against God, the probability of God’s existence is bumped up, according to Swinburne, so that it becomes as probable as not (having a probability of about .5).  Since Swinburne considers a number of inductive arguments or empirical factual claims to each provide a part of the support for the existence of God, it appears that each argument or fact bumps up the probability an average of  a little less than  .1 (seven pro arguments plus one con argument, and the con argument is not considered to be a strong argument, so assuming that the con argument counterbalances one of the weaker pro arguments, that leaves about six pro arguments that when combined together make the probability of the existence of God at least .5, so each argument bumps up the probability .083 on average).

Third, reflection about God’s nature and character shows that God would have good reason to become incarnate as a human being and do the sorts of things that Jesus did, including an impressive miracle like rising from the dead, and since the historical evidence concerning Jesus indicates that Jesus did the sorts of things we would expect God incarnate to do, including rising from the dead, we can conclude that it is VERY probable that Jesus was God incarnate and that Jesus did rise from the dead as the result of divine intervention: God raised Jesus from the dead.  Since, we end up concluding that it is VERY probable that God raised Jesus from the dead, this implies that it is VERY probable that God exists.  Swinburne performs an example calculation that ends up with a probability of .97 for the existence of God.  By “very probable” Swinburne presumably means something like “at least .8”, and he appears to believe this probability to be at least .9.

The probability of the existence of God changes from very low (a probability of about .01) to “at least as likely as not” (a probability of at least .5) after consideration of various inductive arguments for and against God, and then the probability of the existence of God changes again from “as likely as not” to “very probable” (a probability of at least .8) after we consider the likelihood that God would become incarnate and do various things and compare those expectations with the historical evidence that indicates that Jesus did the very sorts of things that God incarnate would likely do.

THE OBJECTION: My logic concerning the resurrection does not allow for such a dynamic probability for the existence of God.  In my probability tree diagram, the existence of God is given a probability just once, at the start of the process, and that probability never changes.  But probability is always determined in relation to a particular collection of evidence and assumptions.

As we work our way through the probability tree, we are exposed to more evidence, and we make further assumptions.  But since the probability of God’s existence was determined and assigned in the very first step, there is no room for revising that probability in the light of new information or added assumptions.  The probability tree diagram, and the probability calculations based on it are thus subject to error because they fail to take into account a basic feature of probability: its relativity to a specific collection of information and/or assumptions.

FEEDBACK LOOP OR ITERATIVE PROBABILITY CALCULATION

Closely related to this objection is the fact that in Swinburne’s logic additional information concerning the alleged resurrection of Jesus that is considered AFTER previous estimation of the probability of the existence of God provides feedback that loops back to impact the probability of the existence of God:

Initial Probability that God Exists–>Probability of the Resurrection–>Revised Probability that God Exists

In the traditional or CLASSICAL approach to Christian Apologetics, there are three main phases of arguments that occur in a particular order:

1.  Prove that God exists.
2. Prove that God has performed specific miracles.
3. Prove that Christianity is the true religion based on specific miracles (i.e. that Jesus is God incarnate and the savior of humankind and that the Bible is the inspired Word of God or that a particular Church is the true church).

Swinburne follows this order to a degree, but he has a feedback loop, so that the evidence considered in phases (2) and (3) provide additional support for the conclusion of phase (1).  This is NOT circular reasoning, because in phase (1) Swinburne provides evidence to support an initial probability of the existence of God  (.5), and then the additional evidence provided in phases (2) and (3) allegedly raise the probability that Jesus is God incarnate to at least .8, and this in turn impacts the probability of the existence of God, raising that probability to also be at least .8.

MY THOUGHTS ON THE LOGIC OF SWINBURNE’S CASE

I agree with Swinburne that attempts to PROVE the existence of God have all failed and are all doomed to fail.  It is much more reasonable for philosophers and Christian apologists to try to show that the existence of God is probable or very probable based on inductive reasoning from empirical evidence.

Furthermore, I agree with the basic idea of Swinburne’s logic, which is that the probability of an hypothesis, such as the existence of God, is relative to a particular collection of factual claims or assumptions.  Swinburne begins with a blank slate, with a state of having ZERO factual evidence for or against the existence of God, and then he begins to consider empirical facts or claims one at a time, revising the probability of the existence of God with each additional fact or claim.  This approach lines up with the common sense idea that we ought to be open minded.  It is wrong to say “My mind is made up, so don’t confuse me with the facts.”  If one keeps an open mind, then new information will often lead one to revise the probability or level of confidence that one places in a particular hypothesis or claim.  Probability calculations or evaluations should be dynamic, and probability calculations or evaluations are relative to a particular collection of facts or assumptions.

If one comes up with an initial probability for the existence of God, and the evidence for this probability does NOT include specific evidence related to the alleged resurrection of Jesus, then that initial probability for the existence of God needs to be re-evaluated AFTER one considers the specific evidence related to the alleged resurrection of Jesus.

If the evidence for the resurrection is strong, and makes the resurrection of Jesus probable, then that evidence and that conclusion about the resurrection could be relevant to the question of the existence of God, and thus the initial probability of the existence of God, that was used to evaluate the resurrection claim, might need to be revised in view of the additional specific information and conclusions about the resurrection.   In order to be open minded, one must be willing to allow evidence of a miracle to influence one’s previous estimate of the probability of the existence of God.