In his book When Skeptics Ask (hereafter: WSA), Norman Geisler presents his general version of a Thomist Cosmological Argument (hereafter: TCA).  The first premise of Geisler’s TCA is this:

1. Finite, changing things exist.  (WSA, p.18)

Geisler provides a very brief argument in support of (1) in WSA.  In Part 4 of this series I showed that Geisler’s brief argument in support of (1) was a stinking philosophical TURD.  It FAILS utterly and completely to support ANY part of premise (1).

In Part 5 of this series I clarified and analyzed a longer and more sophisticated  argument by Geisler in support of just one part of premise (1) of TCA, an argument that is found in his much older book Philosophy of Religion (hereafter: PoR).  This longer argument only supports the simple and obviously true claim that “Something exists”.  In Part 6 of this series, I argued that this longer argument by Geisler FAILS.

In Part 7 of this series, I analyzed and evaluated Geisler’s first argument for the following claim:

21. Changing things exist.

I concluded that this first argument for (21) FAILS.

Now I will attempt to analyze and evaluate Geisler’s second argument for claim (21). Here is the paragraph where Geisler presents this second argument (PoR, page 192):   Key claims in Geisler’s second argument:

31. The argument that all change is illusory is indefensible.

32. Total illusion about ourselves and the world is impossible.

33. If only some change is real…, then it follows that there is at least some real change in real things.

I believe that claim (31) is just a summary of Geisler’s view, and does not play a role in this second argument.  So, the basic logical structure of this argument goes like this:

32. Total illusion about ourselves and the world is impossible.

33. If only some change is real…, then it follows that there is at least some real change in real things.

THEREFORE:

21. Changing things exist.

It seems to me that the consequent of claim (33), i.e. “there is at least some real change in real things” is just an alternative way of stating claim (21), so I will revise the wording of (33) accordingly:

33a. IF only some change is real, THEN changing things exist.

It is immediately apparent that (33a) is FALSE.  The antecedent only requires that ONE change is real, but the consequent asserts that MORE THAN ONE change exists (“things” is plural).  So, if Geisler’s second argument is going to have any chance of success, we need to beef up the antecedent of claim (33a) a bit:

33b. IF two or more changes are real, THEN changing things exist.

Here is the revised 2nd argument:

32. Total illusion about ourselves and the world is impossible.

33b. IF two or more changes are real, THEN changing things exist.

THEREFORE:

21. Changing things exist.

This argument is NOT formally VALID.  We need a claim that affirms the antecedent of (33b) in order to have a formally VALID inference (namely a modus ponens).  Presumably, the claim that affirms the antecedent of (33b) is inferred from claim (32), so that claim (32) has a role in this argument:

32. Total illusion about ourselves and the world is impossible.

THEREFORE:

A. Two or more changes are real.

33b. IF two or more changes are real, THEN changing things exist.

THEREFORE:

21. Changing things exist.

I can see how claim (32) could be used to infer claim (A), because (32) is talking about experiences of two different phenomena:  myself and the world.  (Note: I don’t think Geisler intends for claim (32) to be about multiple selves, but just about ONE self, so I’m going to revise that premise to refer to “myself”.)   We can add an intermediate inference between claim (32) and claim (A):

32a. Total illusion about myself and the world is impossible.

THEREFORE:

B. At least ONE change that I seem to have experienced about myself is real, and at least ONE change that I seem to have experienced about the world is real.

THEREFORE:

A. Two or more changes are real.

33b. IF two or more changes are real, THEN changing things exist.

THEREFORE:

21. Changing things exist.

OK.  We have now analyzed and clarified Geisler’s second argument for the claim that “Changing things exist.”  Here is a diagram showing the logical structure of the argument: 

I am going to start with what is right with this argument, and then proceed to examine the more dubious aspects of the argument.  I set up the final inference from (33b) and (A) to (21) as a modus ponens, so that inference is clearly deductively VALID.  Furthermore, although the inference from (B) to (A) is not a formally VALID deductive inference,  I take it that (B) clearly logically implies (A), so I accept that as a VALID deductive inference.  The assumption I make here is that oneself is something distinguishable from and other than “the world”.  Given that assumption (B) logically implies (A).

There remain three potential problems with this second argument for the claim that “Changing things exist.”:

• Is premise (32) TRUE?
• Can premise (B) be VALIDLY deduced from premise (32)?
• Is premise (33b) TRUE?

I’m going to start with the third question, because premise (33b) is clearly NOT TRUE, but is clearly FALSE:

33b. IF two or more changes are real, THEN changing things exist.

 Two real changes can happen to the SAME THING.  A caterpillar can grow from being small and slender to being much larger and plump, and a caterpillar can then transform into a butterfly.  So, ONE thing can undergo TWO changes.  Therefore, the occurrence of two changes does NOT logically imply the existence of TWO different things that change.

Also, it is not clear and obvious that real changes only occur in “things”.  I can change my mind.  Does that mean that some “thing” has changed?  That depends on whether my mind counts as a “thing”.  Events can change.  My birthday party can change from being dull and boring to being fun and exciting.  But is a birthday party a “thing”?  Are events “things”?  Geisler provides no clarification or definition of the word “thing”, so it is difficult to answer these questions.

Furthermore, the word “thing” is a problematic word in the context of Thomist philosophy.  Aristotle and Aquinas had very specific ideas about what constitutes a “thing” or a “substance”, so whenever the word “thing” appears in relation to Thomist philosophy, one must determine whether this word is being used in some loose ordinary sense of the word, or whether it is being used in a more specific sense in keeping with the metaphysical theories of Thomas Aquinas.

Strictly speaking, premise (33b) is clearly FALSE, and it must be rejected as currently stated.  However, one might be able to revise the wording of (33b) to avoid the counterexample of ONE thing undergoing TWO changes:

33c. IF two or more things change, THEN changing things exist.

Premise (33c) avoids the counterexample of ONE thing undergoing TWO changes, and it avoids the error of inferring the change of a THING from just any sort of change.  However, premise (33c) also appears to be FALSE.

There is no clear reference to time in (33c), and one could reasonably interpret it as having the following meaning:

33d. IF two or more things change at some time or other, THEN changing things exist right now.

But with this clarification in terms of time, we can clearly see that premise (33d) is FALSE, and thus that premise (33c) is also FALSE, if (33d) is a correct interpretation of the meaning of (33c).  My father’s father changed professions at some time or other, and my mother’s mother also changed her profession at some time or other, but both of those people are dead now; neither of them exist at this time, to the best of my knowledge.  So, TWO people have changed at different times in the past, but neither of those two people exist right now.  That is a clear counterexample to premise (33d), so this premise is clearly FALSE.

We could try to repair premise (33d) by making the references to time match up between the antecedent and the consequent.  I happen to know that for the purposes of the Thomist Cosmological Argument it is important to establish that “Changing things exist right now.”  So, we cannot change the consequent of (33d); instead, we must change the antecedent to match the consequent:

33e. IF two or more things have changed in the past and still exist right now, THEN changing things exist right now.

This is the premise that Geisler actually needs to establish for his second argument to work.  Now we need to modify the other premise in the final sub-argument so that the argument will remain logically VALID:

A1. Two or more things have changed in the past and still exist right now.

33e. IF two or more things have changed in the past and still exist right now, THEN changing things exist right now.

THEREFORE:

21a. Changing things exist right now.

OK.  Now premise (33e) appears to be TRUE, and with the modification of the other premise to premise (A1), this sub-argument is also deductively VALID.  So, the question now becomes, has Geisler provided a SOUND deductive argument for premise (A1)?  Here is the argument that Geisler had provided for this premise:

B. At least ONE change that I seem to have experienced about myself is real, and at least ONE change that I seem to have experienced about the world is real.

THEREFORE:

A1. Two or more things have changed in the past and still exist right now.

Because we have modified premise (A) into premise (A1), this inference is no longer a VALID deductive inference.  For example, (B) says nothing about whether the world still exists right now.  

So, premise (B) now also needs to be modified or supplemented in order for Geisler to have a deductively valid sub-argument for (A1).  I am going to split up the reference to the two key phenomena, and I am going to make explicit the assumption that myself and the world are different things:

C. At least ONE change that I seem to have experienced in the past about myself is real, and myself still exists right now.

D. At least ONE change that I seem to have experienced in the past about the world is real, and the world still exists right now.

E. Myself is a thing and the world is a thing.

F. It is NOT the case that the world and myself are the same thing.

THEREFORE:

A1. Two or more things have changed in the past and still exist right now.

Premises (C) and (D) are each supported by premise (32a).  For example, (32a) is a premise supporting (D):

32a. Total illusion about myself and the world is impossible.

THEREFORE:

D. At least ONE change that I seem to have experienced in the past about the world is real, and the world still exists right now.

I just now noticed an ambiguity in (32a), so that needs to be fixed:

32b. Total illusion about myself is impossible and total illusion about the world is impossible.

Now we can lay out the logical structure of my modified/enhanced version of Geisler’s second argument for the conclusion that “Changing things exist right now.”:  

Because I have revised each of the three premises that Geisler provided in order to clarify them or to make the logical inferences valid, and because I have had to add five different unstated assumptions, also in order to make the logical inferences in this argument valid, it is no longer clear that this is Geisler’s argument.  My thought, effort, and skills have gone into the construction of this argument, and it is significantly different from the argument that we started with.  So, even if this turns out to be a solid deductive argument, that will not show that Geisler’s original argument was a solid deductive argument.

It is clear that Geisler’s second argument as originally stated was NOT a SOUND deductive argument, and that it FAILED as a deductively valid proof of the conclusion.  But the above enhanced version of Geisler’s second argument might turn out to be a solid proof, so I will continue to evaluate this enhanced argument in the next post.