Thomas Aquinas: Logical Flaws?

Great Debates
1

St. Thomas Aquinas, the guy who wrote the Summa Theologica and reconciled religion and logic (hell, even combining critical aspects of the two) he was attempting to prove the existence of God, by logic alone, at a time when logic and religion appeared incompatible. I just read the Summa Theologica. If you ask me, he proved the doubters wrong and then some.

Are there any particular flaws in his reasoning, i.e. the Five Proofs? Feel free to rip it to shreds and grind it into oblivion and then nuke the oblivion.

(Don’t limit yourselves to the Five Proofs either.)

As usual, civil responses, please.

2

Yeah, natural selection pretty much removed the need for a Designer.

3

That still doesn’t really answer the question. Natural selection doesn’t, even by Mr. Darwin’s own admission, automatically eliminate the existence of a Creator or Designer. (In fact, most mainstream Christian denominations, save for those weirdos in the backwoods, accept and even teach the theory of evolution and the Big Bang in their schools.)

http://www.darwinproject.ac.uk/letter/DCP-LETT-2534.xml

4

It removes a creator as a necessity.

5

Which god has been proven to exist?

6

And why assume one god?

Even assuming Aquinas has a point, why postulate one unmoved mover? Why not six, or eleven? Why one uncaused cause, and not hundreds? Why one chain of contingency, and one teleological goal, when the ancients had no trouble believing in a whole pantheon of deities; wasn’t there one who handled oceans and earthquakes when he wasn’t busy creating horses, while another one created the olive tree, while another hurled down thunderbolts?

Even if we for some reason grant that a supernatural entity created volcanoes, why assume the same supernatural entity came up with the platypus?

7

Aquinas places great stock in the cosmological argument. His first three proofs are variants of it: Everything in motion requires a mover, everything requires a cause, all existence is contingent. He uses these premises to “prove” the existence of a prime mover/first cause/non-contingent entity from which all else flows.

But there are multiple flaws with this approach. First off, his conclusion contradicts his premises. If everything in motion requires a mover then* there can be no prime mover*. That’s basic logic. Sure, in normal life we’re accustomed to everything having a cause, but that doesn’t mean that uncaused causes can’t exist. (Claiming so in an example of The Problem of Induction). There might be an infinite number of uncaused causes that we haven’t observed yet, and the conclusion that the prime mover is a singular God is unsupported.

8

It’s not that evolution disproves God; it’s just that it nullifies or at least weakens at least one of Aquinas’s arguments.
[QUOTE=St. Thomas Aquinas]
The fifth way is taken from the governance of the world. We see that things which lack intelligence, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to obtain the best result. Hence it is plain that not fortuitously, but designedly, do they achieve their end. Now whatever lacks intelligence cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is shot to its mark by the archer. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God.
[/QUOTE]
It may look like Nature “acts for an end,” to obtain “the best result”; but the theory of evolution explains how this could happen without an intelligent Designer—at least, if the kinds of things Aquinas has in mind here are the kinds of things evolution explains.

9

Really? How did he define God. Not prove such a thing exists, mind you, just how did he define the concept he was setting out to prove.

10

He proved it in the Five Proofs:

[ol]
[li]The Unmoved Mover.[/li][li]First Cause[/li][li]Argument From Contingency[/li][li]Argument From Degree[/li][li]Teleological Argument[/li][/ol]

Now, one by one.

The Unmoved Mover goes like this: Some things are in motion. Things can’t move themselves. An infinite chain of movers is impossible. Therefore, there must be an unmoved mover who moves all things. This is what we understand to be God.

The First Cause: Kinda the same thing, but with causation. All things have a cause. Infinite chain of causes? (imitate “wrong” buzzer from “Family Feud”) Can’t happen. Therefore, there must be a chain of causes that is the cause of all causes. This cause is understood as God.

Contingency Argument: Things in the universe either exist or don’t. The things that exist are either contingent or they aren’t. It is impossible for everything in the universe to be contingent, otherwise we end up with a time where nothing existed, and nothing could bring forth existence. This is obviously false because we know we exist. Therefore, there must be a necessary being to bring forth existence. You guessed it: God, or who we understand to be God.

Degree Argument: Different kinds of perfection may be found in varying degrees across the universe. These degrees factor in a sort of ultimate standard of perfection. Perfection, therefore, must have a pinnacle. One guess what this pinnacle is.

And, finally, the Teleological Argument: All natural bodies follow laws of conduct. Some of these are unintelligent (but others not). Laws of conduct are characteristic of intelligence. Therefore, there exists an intelligent being that created these laws. One guess…

Now, this makes sense based on what we have learned since Aquinas’ day. We know for a fact that there was indeed a beginning for the universe. There are indeed bodies that follow laws of conduct. (Think about animals in the forests and the jungles, or, for something more inanimate, rock formations and their erosion.) Can a rock formation move itself? Of course not! Can we move ourselves? Of course not. We require muscle and bone and a functioning brain in order to do so. There are things that don’t exist or do exist. “Cognito ergo sum,” to borrow from Rene Descartes. Therefore, it stands to reason that there must be a First Cause, otherwise existence itself cannot exist.

11

I could see a parallel universe where something like an uncaused cause might happen, but I have considerable trouble understanding how it could happen here, given what we know of physics.

12

“Perfection must have a pinnacle”? This is a meaningless phrase-perfection doesn’t have to have a “pinnacle”. Describe the “Perfect” book, movie, cookie or flower. The Pinnacle of Perfection must be your god? A perfect circle or triangle has never been described as “godlike” as far as I can remember and besides, if I remember right, your god lost his temper a couple of times(so much for his perfect record.)

13

Why can’t there be two or twelve or twenty unmoved movers?

Why can’t there be multiple uncaused causes?

…or gods.

Well, that one’s just silly. There’s a taller man than me, and a taller man than him; must there be an infinitely tall man? There’s also a shorter man than me, and a shorter man than him; must there be an infinitely short one?

There are powerful evildoers in this world. Must there be an all-powerful evildoer? Who’s also all-evil?

Nine guys? Ninety?

14

Besides, the universe we now inhabit may not have been caused by your proposed “First Cause”. It may very well be an aftereffect of the death of a previous universe, or leakage from an alternate universe. There are gaps in our knowledge, and no real evidence to fill those gaps with your god.

15

At that, we could assume – for the sake of argument – that there is one uncaused cause: an unmoved mover who set all other things in motion, such that every last chain of contingency could be traced back to that lone entity’s teleological goals.

We don’t have to, but we could.

And we could just as easily assume he then committed suicide and had been dead ever since. I’ve seen people set things in motion – literally and figuratively – causing this and that with a plan in mind, and, well, some of them went on to kill themselves.

Again, I see no reason to assume one uncaused cause instead of dozens or hundreds. But if I for some reason did, why assume one who survived?

Why assume one who still exists?

16

What if the uncaused cause is a really simple one? Too simple to be attributed any of the properties of a being - does it still deserve to be called ‘God’?

17

Well, Newton’s First Law says an object at rest stays at rest until acted upon by a force, likewise, an object in motion stays in motion for the same reason. The “force” acting on the object is the “cause.” For example: Throw a baseball across an open field. The ball will stop moving eventually due to gravity. Gravity is the cause (or force, if you prefer) making the ball stop. However, gravity has to have a cause too because we know it exists. It didn’t just pop up outta nowhere. There has to be a cause for all that exists. I exist, therefore, something happened to cause my existence. Get it? However, Aquinas’ point was that infinite chains of causes are impossible. The Big Bang originated from an extremely hot, extremely dense mass, which in itself had to have a cause. Otherwise, it could not exist, therefore nothing could exist, and we wouldn’t be arguing about this right now.

18

Since you believe there could be one uncaused cause, do you believe there could be multiple uncaused causes?

19

As was already pointed out above, this reasoning rules out an uncaused prime mover. Either there can be exceptions to cause and effect, in which case a prime mover isn’t the only explanation; or there can’t be, in which case there can’t be a prime mover.

20

But there are no laws that state one thing and one thing only was that cause, or that whatever it was that caused this universe was a “first” cause. Once again, it could have been the aftereffects from a previous universe, or an glitch from another universe.

There is NO “First Cause” Law.