Do Aquinas's "5 Ways" actually demonstrate the existence of God?

Answer 1

Aquina's "Five Ways", or arguments for God, can be summarized as follows:

1) The argument of the unmoved mover
2) The argument of the first cause
3) The argument of necessity
4) The argument of perfection
5) The argument of design

The first two, 1) & 2), have the same structure, the only difference being that the first refers to motion arising from motion, the 2nd refers to causes that themselves have prior causes. Questions of this nature is the bread and butter of physics, there have been many proposals, some even which are mathematically sound, but not yet empircally corroborated as fact. The weakness of arguments 1) & 2) is that while it hypothesizes that there must be an orginal mover/cause, it then takes the unwarranted leap and makes the claim that it is God, which attributes have already been defined elsewhere. Why should such an original mover/cause be particularly concerned with the sexual habits of humans, for example? No argument is made for the connection between the two.

Argument 3) first notes that things come into and out of existence, so therefore everything has had a time when it did not exist. Therefore there must have been a time where nothing existed. If there was nothing, how could something have brought something into existence, unless some agent was eternal? That agent is identified as God, and this argument suffers from the same weakeness as 1) & 2) A further weakness is assuming that just because things come in and out of existence, there had to be a point in time where nothing existed. Not necessarily true, things can flit into and out of existence for all eternity, there's nothing logically impossible about that.

4) First notes that we see things in various stages of imperfection, so that "therefore", we can arrange items in order of perfection through imperfection and presumably gross imperfection. Even if we don't see actual examples of absolute perfection, the sequence suggests the existence of such absolute perfection, and, again, that has to be God. Yes, but why would an absolutely perfect being be unusually concerned with the way humans want to do sex? Once again, the fallacy of this argument is the assumption that there necessarily has to exist some ideal terminus in the sequence of imperfections that we do see. I could arrange all humans in the order of height, so that there would be a real tallest human being, but that does not mean therefore there has to exist a human that is infinitely or even perfectly tall.

The last one, 5), is the Intelligent Design argument, which has already been thrown out of court in the Dover vs Kitzmiller case in 2005. This is probably the most appealing argument for the existence of God for most, because we do see countless examples of astonishing complexity and even beauty in nature, and many are baffled how such things could "come about by blind chance", and so God is the Great Designer. It is very hard for many to comprehend how complexity can in fact spontaneously emerge from seeming disorder or simpler forms, but it's a vigorous field of study, strongly supported by computer simulations, and commerical applications have already begun. For many in the field, it's an engrossing subject, but for the rest, it will always be a personal choice of belief. Many cannot look at nature and say that God wasn't the author of it.

Answer 2

Of course not. You cannot demonstrate the existence of something that does not exist.

Answer 3

It give rational reasons to believe in the existence of God.

Answer 4

it demonstates that there must be an uncreated crator, "unmoved mover" that we title God. not that the catholic God exists, Aquinas proves that later on.

Answer 5

The argument for "First cause" is pretty powerful.

Answer 6

Not really. See your previous question.

Answer 7

nope, ex contingentia