How do atheist\scientists account for Thomas Aquinas?

[jon462]

Many philosophers have torn holes in rational proofs of God made by Descartes, Anselm, Augustine, etc., so much so that even religious philosophers such as myself rarely use their proofs. However, as far as I am aware, no one has ever been able to disprove or even discredit Thomas Aquinas' proofs of God's existence, which are scientific in nature. I think that a skeptic in the tradition of David Hume could easily do so, however in my experience most modern atheists are not skeptics but scientists (you cannot be a skeptic and a scientist). I cannot comprehend how an intellectually honest scientist could read Aquinas' proof and not confess that God must exist.

For those of you not familiar with his proofs here is the full text: http://www.braungardt.com/Theology/P...as_aquinas.htm

The 4th and 5th proofs are a little too Aristotelian I think and different than the first three, so I would rather keep this discussion to the first 3 proofs are very relevant.

1.The first and most obvious way is based on the existence of motion. It is certain and in fact evident to our senses that some things in the world are moved. Everything that is moved, however, is moved by something else, for a thing cannot be moved unless that movement is potentially within it. A thing moves something else insofar as it actually exists, for to move something is simply to actualize what is potentially within that thing. Something can be led thus from potentiality to actuality only by something else which is already actualized. For example, a fire, which is actually hot, causes the change or motion whereby wood, which is potentially hot, becomes actually hot. Now it is impossible that something should be potentially and actually the same thing at the same time, although it could be potentially and actually different things. For example, what is actually hot cannot at the same moment be actually cold, although it can be actually hot and potentially cold. Therefore it is impossible that a thing could move itself, for that would involve simultaneously moving and being moved in the same respect. Thus whatever is moved must be moved by something, else, etc. This cannot go on to infinity, however, for if it did there would be no first mover and consequently no other movers, because these other movers are such only insofar as they are moved by a first mover. For example, a stick moves only because it is moved by the hand. Thus it is necessary to proceed back to some prime mover which is moved by nothing else, and this is what everyone means by "God."
Aquinas predates Newton by a couple of hundred years, but it seems to me this is a logical and obvious conclusion of Newtons laws of physics.

2. The second way is based on the existence of efficient causality. We see in the world around us that there is an order of efficient causes. Nor is it ever found (in fact it is impossible) that something is its own efficient cause. If it were, it would be prior to itself, which is impossible. Nevertheless, the order of efficient causes cannot proceed to infinity, for in any such order the first is cause of the middle (whether one or many) and the middle of the last. Without the cause, the effect does not follow. Thus, if the first cause did not exist, neither would the middle and last causes in the sequence. If, however, there were an infinite regression of efficient causes, there would be no first efficient cause and therefore no middle causes or final effects, which is obviously not the case. Thus it is necessary to posit some first efficient cause, which everyone calls "God."
Again, seems to me obvious to anyone with an understanding of causality, which always makes me wonder how so many scientists can be atheists (in that science is based on causality

3. The third way is based on possibility and necessity. We find that some things can either exist or not exist, for we find them springing up and then disappearing, thus sometimes existing and sometimes not. It is impossible, however, that everything should be such, for what can possibly not exist does not do so at some time. If it is possible for every particular thing not to exist, there must have been a time when nothing at all existed. If this were true, however, then nothing would exist now, for something that does not exist can begin to do so only through something that already exists. If, therefore, there had been a time when nothing existed, then nothing could ever have begun to exist, and thus there would be nothing now, which is clearly false. Therefore all beings cannot be merely possible. There must be one being which is necessary. Any necessary being, however, either has or does not have something else as the cause of its necessity. If the former, then there cannot be an infinite series of such causes, any more than there can be an infinite series of efficient causes, as we have seen. Thus we must to posit the existence of something which is necessary and owes its necessity to no cause outside itself. That is what everyone calls "God."

The first two proofs prove that there must be a creator (God). The third one proves he has no cause, i.e. he is eternal. For those of you interested, the 4th proves he is perfection and goodness, the 5th that he is still a controlling force in the world (however, as I said Id rather just discuss the first three).

[Zygote]

David Hume, among other western philosophers, was the first to outline the serious flaws in Aquinas' agruments. Since these discoveries, Aquanis' arguements have proven to hold little to no weight amongst modern non-theistic philosophers. I wrote a paper critiquing Aquinas in university, but can't seem to find where it is right now. When i have some time i'll make specifc comments.

[jon462]

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David Hume, among other western philosophers, was the first to outline the serious flaws in Aquinas' agruments. Since these discoveries, Aquanis' arguements have proven to hold little to no weight amongst modern non-theistic philosophers. I wrote a paper critiquing Aquinas in university, but can't seem to find where it is right now. When i have some time i'll make specifc comments.

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I would appreciate that. I am not familiar with this critique in particular, however I am familiar with Hume. As I mentioned above, I can see how a skeptic would dismiss it - quite easily since Hume dismisses outright cause and effect, and the crux of Aquinas argument is based on cause and effect. However, I am I not correct that skeptics in modern science are even rarer than Christians? I think if you use Hume's argument to dispute Aquinas, then you have to be willing to say that science itself is a religion - since it too is based on causality (which a few philosophers of science have claimed but most practicing scienctists arent ready to admit). This is why I am interested in seeing how a non-skeptic atheist would handle Aquinas. In my opinion, you can really use David Hume to dispute any argument arguing any point about anything, so its not exactly fair.

[BZ_Zorro]

Who?

[gumpzilla]

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Thus it is necessary to posit some first efficient cause, which everyone calls "God."

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Some people call it the big bang. EDIT: Let me also comment that first cause arguments seem extremely weak. Why is God exempt from the requirement of being caused, and if you're going to assume that you can have something exempt of that requirement, then the argument is pointless in the first place as you could just as well choose something else.

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If it is possible for every particular thing not to exist, there must have been a time when nothing at all existed.

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I don't think this makes a lick of sense. Let me make an analogy. Let's say I have a set of integers {1, 2, 3}. Now let's say that at each time step, I remove the smallest number in the set and add the smallest natural number not in the set to the set, i.e {1,2,3} -> {2,3,4} -> {3,4,5}. Consider membership in the set existence. Every natural number will be nonexistent at some point, but this does not demonstrate that there is a time where nothing exists - the set is never empty.

[jon462]

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Thus it is necessary to posit some first efficient cause, which everyone calls "God."

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Some people call it the big bang. EDIT: Let me also comment that first cause arguments seem extremely weak. Why is God exempt from the requirement of being caused, and if you're going to assume that you can have something exempt of that requirement, then the argument is pointless in the first place as you could just as well choose something else.


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Yes, the big bang. But what caused the big bang? And what caused that which caused the big bang? The point is clear that there has to be something that was the first cause, and since it is the first cause, it could not have been caused itself - i.e. it must have always existed. You can arbitrarily call this thing whatever you like: Aquinas calls it God.

[gumpzilla]

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Yes, the big bang. But what caused the big bang?

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What caused God?

Also, to say that you can call it whatever you like is kind of disingenuous if what you're going to call it is an entity that you are supposing elsewhere has particular properties. In other words, fine, suppose a first cause and call it God, but now take what we normally refer to as God and call it Blapskopolis or something.

[jon462]

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If it is possible for every particular thing not to exist, there must have been a time when nothing at all existed.

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I don't think this makes a lick of sense. Let me make an analogy. Let's say I have a set of integers {1, 2, 3}. Now let's say that at each time step, I remove the smallest number in the set and add the smallest natural number not in the set to the set, i.e {1,2,3} -> {2,3,4} -> {3,4,5}. Consider membership in the set existence. Every natural number will be nonexistent at some point, but this does not demonstrate that there is a time where nothing exists - the set is never empty.

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Ok, Im not sure you will be satisfied with my answer, but here goes. The notion of possibility when applied to existence, in the Aristotelian\Thomistic since, implies that - given an infinite amount of time - a thing which can possibility exist must at sometimes exist and at other times not exist. If it always existed, then its existence would be necessary, not possible. Since all possible things at one point exist and at one point do not exist - well given an infinite amount of time every possible combination of existence and non-existence would occur - including the instance of no possible existences existing. (clearly it is impossible for their to be a time when nothing existed, as then nothing could be created and there for nothing would ever exist, so their must be one thing which exists by necessity, i.e. God)

As for your above example, well maybe I will get really lucky and someone with a better understanding of Aquinas and\or mathematics will chime in. It seems to me you have set up an arbitrary rule that the universe does not follow. How can you say " remove the smallest number in the set and add the smallest natural number not in the set to the set" - who is to say that that the set will not be incresed to more than 3 numbers, or that 5 will change to -3, etc. - and at one point in time it will be reduced to 0 numbers?

[gumpzilla]

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Since all possible things at one point exist and at one point do not exist - well given an infinite amount of time every possible combination of existence and non-existence would occur - including the instance of no possible existences existing.

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No, this does not follow. Say that object A and object B must always exist together, for example. Then you can't realize instances where object A and object B exist separately. More fundamentally, to say that given an infinite amount of time every possible combination must be reached is an assumption - not unlike the kinds of assumptions that go into statistical mechanics, incidentally. It could very well just cycle through a relatively small subset of possible combinations. If you assume a countable number of things, then it might be that there are a countable number of combinations that can be reached rather the uncountable number that you are suggesting by saying we must explore the entire power set of existence/nonexistence sets.

[jon462]

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Since all possible things at one point exist and at one point do not exist - well given an infinite amount of time every possible combination of existence and non-existence would occur - including the instance of no possible existences existing.

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No, this does not follow. Say that object A and object B must always exist together, for example. Then you can't realize instances where object A and object B exist separately. More fundamentally, to say that given an infinite amount of time every possible combination must be reached is an assumption - not unlike the kinds of assumptions that go into statistical mechanics, incidentally. It could very well just cycle through a relatively small subset of possible combinations. If you assume a countable number of things, then it might be that there are a countable number of combinations that can be reached rather the uncountable number that you are suggesting by saying we must explore the entire power set of existence/nonexistence sets.

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I do not wish to defend his third law anymore. This is because I do not completely understand it, and I wasnt quite sure that the text you quoted made any sense as I wrote it - it was my feeble attempt to explain it and very possibly not what Aquinas would have meant. I am much more comfortable defending the first two. I am not conceding the point - I simply am not adequate to defend Aquinas here and do not wish to make an ass of myself.