Lessing’s Broad Ditch and Brad’s Lesser Ditch

LESSING’S BROAD DITCH

Quotations are from Lessing’s essay “On the Proof of the Spirit and of Power” from Lessing’s Theological Writings (hereafter: LTW), edited by Henry Chadwick.

Reports of Miracles are not the same as Direct Observation of Miracles

“The problem is that reports of fulfilled prophecies are not fulfilled prophecies; that reports of miracles are not miracles.” (LTW,p.52)

“What is asserted is only that the reports which we have of these prophecies and miracles are as reliable as historical truths ever can be.  And then it is added that historical truths cannot be demonstrated: nevertheless we must believe them as firmly as truths that have been demonstrated.” (LTW, p.53)

Because we cannot directly observe Jesus performing miracles now, we must rely upon historical evidence to base our beliefs about whether Jesus performed any miracles and what specific miracles he performed.  But historical evidence can only yeild probability, not certainty.

We Cannot Build a Demonstration or Proof upon Historical Premises

“If no historical truth can be demonstrated, then nothing can be demonstrated by means of historical truths.  That is, accidental truths of history can never become the proof of necessary truths of reason.” (LTW, p.53)

If the premises of an argument are only contingent and probable, then the argument cannot show the conclusion to be necessary or certain.

Historical Beliefs are Insufficient Grounds for Risking Something of Great Worth

“We all believe that an Alexander lived who in a short lifetime conquered almost all of Asia.  But who, on the basis of this belief, would risk anything of great, permanent worth, the loss of which would be irreparable?”  (LTW, p.54)

To reasonably put something of great worth at risk, we must have great certainty in the truth of the beliefs that support this decision, but historical evidence is insufficient to provide that level of certainty.

Can Historical Beliefs provide a Proper basis for Metaphysical Beliefs? 

 “If on historical grounds I have no objection to the statement that Christ raised to life a dead man; must I therefore accept it as true that God has a Son who is of the same essence as himself?” (LTW, p.54)

“If on historical grounds I have no objection to the statement that this Christ himself rose from the dead, must I therefore accept it as true that this risen Christ was the Son of God?” (LTW, p.54)

If a claim is acceptable as an historical claim does that mean that it can provide sufficient evidence to establish a metaphysical or theological claim?

There is a Broad Ditch between Historical Beliefs and Metaphysical Beliefs

 “But to jump with that historical truth to a quite different class of truths, and to demand of me that I should form all my metaphysical and moral ideas accordingly; to expect me to alter all my fundamental ideas of the nature of the Godhead…” based on such historical beliefs is bad reasoning [according to Lessing] (LTW, p.54)

“It is said: ‘The Christ of whom on historical grounds you must allow that he raised the dead, that he himself rose from the dead, said himself that God had a Son of the same essence as himself and that he is this Son.’  This would be quite excellent!  if only it were not the case that it is not more than historically certain that Christ said this!”  (LTW, p.54-55)

“That, then, is the ugly, broad ditch which I cannot get accross, however often and however earnestly I have tried to make the leap.”  (LTW, p.55)

One cannot legitimately infer metaphysical and theological conclusions, such as that Jesus was the divine Son of God, on the basis of historical beliefs, such as that Jesus died on the cross and then rose from the dead, even if those historical beliefs are well-grounded in historical evidence.

PROBLEMS WITH LESSING’S DITCH

There are at least two basic problems with Lessing’s Ditch.  The Ditch can be narrowed from both sides.  On the one hand, we can lower the bar for the acceptance of metaphysical and theological claims/beliefs.  Lessing appears to be a rationalist concerning metaphysics and theology.  He expected metaphysical and theological claims to be demonstrated in a way similar to the rigorous proofs of geometry.  But now, in the age of science, we no longer demand certainty for general theories and principles.

Probability is good enough for scientific theories and principles, certainty is not required.  Richard Swinburne is a leading philosopher of religion and defender of theism, and his book making the case for theism ends with the conclusion that the hypothesis that God exists is more likely than not.  So, in this age of modern science, we might reasonably join with Swinburne in lowering the bar for the acceptance of metaphysical and theological claims to one of probability.  If it could be shown that the basic theological claims of Christianity were very probable, that might reasonably be considered to be sufficient reason to accept those claims.

The ditch could, in theory, also be narrowed from the side of historical claims.  Scholars have carefully and critically studied the historical evidence concerning the life and ministry of Jesus for over two centuries, so it is possible that a case could be made for certain claims about Jesus that would show those claims to be very probable.

If we lower the standard for acceptability of metaphysical and theological claims and if a Christian apologist (such as William Craig or Gary Habermas) can put together a solid case for some key historical claims about Jesus, and show those claims to be very probable, then it would be possible (in theory, at least) to close the gap between historical claims and the metapysical or theological conclusions that are based upon those claims.

BRAD’S LESSER DITCH

A basic principle of logic and scholarship is that a strong claim is less likely to be true than a weaker version of the claim.  Conversely, a weaker version of a claim is more likely to be true than the strong version of it.  So, I’m going to borrow from Lessing’s reasoning, but construct a somewhat weaker version of a gap between historical claims about Jesus and theological claims about Jesus (my “lesser ditch”).  This modified version of Lessing’s Ditch will, I believe, get around the above objections, at least.  So, I believe this to be an improvement on Lessing’s Ditch.

Lessing’s discussion focuses on historical claims about Jesus and theological claims about Jesus, and he appears to be contemplating an argument that goes something like this:

1. Jesus taught that God had exactly one Son of the same essence as God. (an historical claim about Jesus)

2. Jesus claimed to be that Son of God. (an historical claim about Jesus)

3. Jesus rose from the dead. (an historical claim about Jesus)

Therefore:

4. Jesus is the unique Son of God who has the same essence as God. (a theological claim about Jesus)

There are various problems with this argument, some which can be fixed or alleviated.  First, not only does this fall short of being a conclusive proof, but as it stands the conclusion simply does not follow from the premises.  We need to make one or more assumptions explicit to bridge the logical gap between the premises and the conclusion.   Another problem is that the expression “Son of God” is vague and unclear.   Another problem is that the claim “Jesus rose from the dead” is best understood as the synthesis of a few separate historical claims. (3) summarizes multiple historical claims.

I’m going to formulate a similar argument that is a bit clearer and more explicit:

5. Jesus claimed to be the one-and-only savior of humankind. 

6.  Jesus claimed to be fully human.

7.  Jesus claimed to be fully divine.

8.  Jesus died on the cross on a Friday evening.

9. Jesus remained dead for at least 24 hours after he died on the cross.

10.  Jesus was alive and walking around on Sunday, only about two days after the Friday when he was (supposedly) crucified.

11. If (5), (6), (7), (8), (9), and (10) are true, then Jesus is the one-and-only fully human and fully divine savior of humankind.

Therefore:

12. Jesus is the one-and-only fully human and fully divine savior of humankind.

Premises (5), (6), (7), (8), (9), and (10) are all historical claims about Jesus.  Claim (11) asserts that there is a logical or epistemological relationship between those historical premises and the theological conclusion that states a basic Christian belief about Jesus’ nature and role in the cosmic scheme of things.

None of the premises in this argument is certain.  There are reasonable doubts about each and every one of the premises in this argument. Each premise has a significant chance of being false. But for the argument to be successful, each and every one of the seven premises must be true.

As Lessing pointed out, historical claims, especially historical claims about figures of ancient history, can only be probable to some degree, not certain.  In my view it is probably false that Jesus claimed to be the one-and-only savior of humankind, and it is probably false that Jesus claimed to be fully divine.  In my view it is probably false that Jesus was alive and walking around on Sunday, just a couple of days after he was crucified.  So, in my view this argument is a complete failure.

However, even if we are very generous and grant that ALL of the historical claims in this argument are very probable (with a probability of .8), and that premise (11) was also very probable, the conclusion is NOT shown to be very probable.  Suppose (for purposes of illustrating a point) that the truth of each of the premises was independent of the truth of the other premises.  In that case, the probability that ALL SEVEN premises were true would be equal to the following:

.8 x .8 x .8 x .8 x .8 x .8 x .8

=  .64 x .64 x .64 x .8

=  0.262144 x .8

= 0.2097152

This number is too precise, given that the input numbers are only estimated probabilities.  So, the probability that ALL SEVEN premises are true is about .2  (two chances in ten), based on the above assumptions.

Bumping the probability estimate for each of the premises up to .9 (nine chances in ten) does not greatly improve the outcome:

.9 x .9 x .9 x .9 x .9 x .9 x .9

= .81 x .81 x .81 x .9

=  0.531441   x .9

= 0.4782969

Again, this number is too precise.  Assuming that each of the seven premises has a probability of .9, and assuming that the truth of each premise is independent of the other premises, then the probability that ALL SEVEN premises are true is about .5 (five chances in ten).  So, even if we consider this best-case-senario for Christian apologetics, the conclusion isn’t even shown to be more probable than not!  The conclusion is clearly NOT shown to be very probable.

Assessing the probability that ALL SEVEN claims are true is not quite this simple, however.  The asessment is made more complicated by the fact that the truth of each premise is NOT independent of the truth of the other premises.    For example, if Jesus really was alive and walking around on Easter Sunday , i.e. if premise (10) was true,  then that would be a very powerful bit of evidence AGAINST the truth of premise (8), the claim that Jesus died on the cross on Friday.

Also, if Jesus claimed to be fully human, premise (6),  then this makes it less likely that he would also claim to be fully divine, premise (7), because the idea of being both fully human and fully divine appears to be illogical.  Now,  perhaps some sharp and sophisticated philosopher or theologian can present careful arguments showing that the idea of a person who is both fully human AND fully divine is a logically coherent idea.  However, what matters here is that these ideas APPEAR or SEEM to be logically incompatible.  Given that there is an appearance of a logical contradiction here, it follows that it is unlikely that someone would attribute both of these characteristics to the same being or person.  So, the truth of some of the premises constitutes evidence for the falsehood of some of the other premises.

But the opposite relationship may be the case with some of the premises as well.  If Jesus really did claim to be fully divine, premise (7), then that makes it more likely that he also claimed to be the one-and-only savior of mankind, premise (5).  And if Jesus really claimed to be the one-and-only savior of mankind, that would make it more likely that he also claimed to be fully divine.  So, premises (5) and (7) have a positive relationship towards each other.

Although in some cases the truth of one premise would make another premise less likely to be true, there are no premises that logically entail the falsehood of another premise.  Although in some cases the truth of one premise would make another premise more likely to be true, there are no premises that  logically entail the truth of another premise.  Furthermore, in most cases the degree of increase or decrease in probability is relatively small.  For example, Jesus claiming to be the one-and-only savior of humankind does NOT amount to overwhelming or even powerful evidence for the premise that Jesus claimed to be fully divine.  It is very possible that Jesus claimed the former but not the latter.

Furthermore, the one case where there does appear to be a fairly strong degree of impact of the truth of one premise on the probability of another premise, this is in favor of a skeptical conclusion.  Specifically, if we knew for certain that Jesus died on the cross on Friday evening, premise (8), then that would be very powerful evidence AGAINST the claim that Jesus was alive and walking around on Easter Sunday, premise (10).    So, the truth of (8) has a very strong impact on decreasing the probability of premise (10).   Similarly, if we knew for certain that Jesus was alive and walking around on Easter Sunday, then this would be very strong evidence AGAINST the claim that Jesus died on the cross on Friday, just a couple of days previous.  So, the truth of premise (10) has a very strong impact on decreasing the probability of premise (8).

Finally, it is clear that there is a mixture of positive and negative relationships between the truth of some premises and the probability of other premises.  Given all of these qualifications about the influence and impact of the truth of each premise on the probability of other premises, it seems to me that the simple calculation, which assumes that the truth of each premise is independent of the truth of the other premises, is NOT far off the mark, and yeilds a conservative assessment, from the point of view of skepticism.  In other words, it looks to me like a more careful and sophisticated assessment of the probability that ALL SEVEN premises would be true, given the generous assumption that each premise has a probability of .9, would arrive at a probability that is lower than the probability we arrived at earlier by means of the simplifying asumption that the truth of each premise was independent of the truth of the other premises.  The probability would end up being less than .5 (less than five chances in ten).

One final point.  I have some sympathy for Lessings view that the degree of certrainty that historical claims, especially ancient historical claims about Jesus, can have is insufficient to justify a decision involving the risk of something of great worth.  Specifically, because accepting the Christian faith requires making significant commitment to a way of life and to particular moral values and to various metaphysical beliefs, I do not think it is reasonable to base such a decision upon modest probabilities, such as “it is more probable than not that God exists” or “it is more probable than not that Jesus is the one-and-only fully human and fully divine savior of humankind”.  I think that such life changing beliefs ought to be established to a high degree of probability.  Such basic theological beliefs should not be accepted unless they can be shown to be very probable, to have a probability of at least .8 or .9.  If this is a reasonable standard, then there appears to remain a gap or ditch between the best-case-scenario probability for the basic Christian theological beliefs about Jesus (in the area of .5) and the probabililty required for reasonable acceptance of this belief (in the area of .8 or .9).