Recently, a quarrel between Latins pretending to be scholastics and Eastern polemists pretending to be hesychasts has been going on. On top of what went on in Middle Ages, what with Photius, Caerularius, Gregory Palamas, Markos Evyenikos of Ephesus vs Cardinal Humbert, Pope St Leo IX, Aquinas' "contra Errores Grecorum" & other things like that, not to mention treasons on both sides in crusading and similar military history. There are ow Latins who find more faults with Greeks than older Latins did, and Greeks who find more fault with Latins, than former Greeks did.
The former attacking hesychasm as "hypnosis" and the latter attacking scholasticism as "calculating religion taking unduly the place of a real love story with God" or even "atheism". I heartily am against both these stances, and preparing to answer the neo-Latin one. Here, however, I will try to answer the one that takes a shorter answer, because a complete misunderstanding is a thing that does not take very long to mend with a shortish explanation.
An article of the Summa is not the only format open to a scholastic. St Robert Bellarmine used another format, he often eough enumerated the positions taken by diverse authors professing Christianity, before saying "and the Nth opinion is the true one". There have been authors attacking it because third article of second question begins with "seemingly, there is no God".
Let us get it straight with a very august literary parallel. The Gospel. When I first read "if you are the Son of God, make bread of these stones" I very briefly wondered whether Our Lord would do it. But if so, why was it suggested by the devil? After all, Our Lord is not known for agreeing with the devil. Bad men make deals with the devil and get punished. Weak men make deals with the devil and very narrowly escape being punished. Dr Faustus vs that knight who won his bride after the devil built a castle and won back his soul when the hermit told the devil (but the bride's father had already given away the bride, I think) a real castle has a chapel (which the devil had been unable to provide). But after getting the answer "man liveth not of bread alone, but of every word that is from God", the devil of the Gospel could not make me believe even a split second that Our Lord would jump or worship the devil.
Now the articles of the summa, especially the most important ones, follow this model. And the first one gives a very broad hint about it:
Question I, about Sacred Doctrine, Article 1, and I paraphrase the title as: Whether on top of all merely natural doctrine revealed by senses and by reason there is need for another thing sacredly revealed by God.
Objection 1: It would seem that apart from merely natural doctrine, there is no need for sacred doctrine, because ...
Yeah, right bloke! That is a very heavy volume where I find these words, and the title says Sum of Theology, that being a word for sacred doctrine! So, if there is neither any sacred dotrine or any need for it, what is the thick volume written about?
By the way: Article nine of same first question similarily begins by "saying" it would be inappropriate for sacred doctrine to use similes and metaphors - only to say in the end that it does use metaphors. Article ten says it has more than just the literal sense. After reading articles nine and ten, I am of course not impressed by people saying the "six days should ot be taken literally, they are really an allegory for billions of years" - since any possible figurative wording about six days still belongs to "literal sense" and any "allegoric sense" is about something quite else than the first creation: like sleep of Adam and Eve coming out of his side, is allegorically about Our Lord "sleeping" on the Cross, and Holy Church coming out of his side.
You do not get very many more lines before you read the reason why there is a need for sacred doctrine on top of all secular ones. So, any reader who gets as far as Q II Art 3 "Whether there is God" and finds the first words "It would seem, there is no God" would already know the work well enough to know that that is so NOT what St Thomas Aquinas presents as the truth.
I will cite that article in full. With comments.
Article 3. Whether God exists?
Objection 1. It seems that God does not exist; because ...
I have already explained this is not what saint Thomas thinks, just as the Gospeller was not hoping for Our Lord to make bread out of stones.
... if one of two contraries be infinite, the other would be altogether destroyed. But the word "God" means that He is infinite goodness. If, therefore, God existed, there would be no evil discoverable; but there is evil in the world. Therefore God does not exist.
A heavy one. Modern atheism at its most impressive prefigured. "After Auschwitz, do you really believe there is a God?" St Thomas who had not heard about WW-II probably thought of other evils, such as the ones attributed by the manicheans he had previously opposed to "evil maker of matter" - fire that burns, sex that seduces, water that drowns, power that corrupts ...
Objection 2. Further, it is superfluous to suppose that what can be accounted for by a few principles has been produced by many. But it seems that everything we see in the world can be accounted for by other principles, supposing God did not exist. For all natural things can be reduced to one principle which is nature; and all voluntary things can be reduced to one principle which is human reason, or will. Therefore there is no need to suppose God's existence.
Another classic. "Earlier on people did not know about Big Bang, and how Earth circles sun because equilibrium of previous movement and of gravitational tug into sun works out that way, and how lightnings come about by electricity and how lightnings and ammoniac and stuff in first seas combined into simple amino-acids and how amoeba evolved into man by mutations and natural selection, so they said like 'it is God who made the stars' or 'it is God who makes the seasons' or 'it is God who makes sushine and lighting' or 'it is God who made life and created it in many species' but NOW we know better: the Bible was written by people without scientific knowledge." In St Thomas Aquinas' day the typical atheist would have been an astrologer who said all came about by movement of stars. It might also be some crank who had dug up Epikouros and Demokritos. And St Thomas might well have been referring Epikouros and Demokritos (or their Latin successor Lucretius) just to be complete in his refutations.
Actually these are the only two arguments for atheism. Any other argument against Christianity works quite as well as an argument for some other religion, every other argument against Catholicism might be an argument in favour of some other confession.
On the contrary, It is said in the person of God: "I am Who am." (Exodus 3:14)
St Thomas, before he goes on to either positively prove there is a God or answer the charges of atheism, does not give any answer of his own, but quotes - the word of God. Same one, by the way, which is responsible for Byzantine Iconography, halo aroud Jesus' head bearig a cross shape inscribed with the words "O Ω N". Only then does he go on to what he has to say himself, and first off he explains positively, totally ignoring the arguments of atheism:
I answer that, The existence of God can be proved in five ways.
The five way argument has been criticised for leadig to a God who is not the Biblical one. Not quite right, a reader of the Summa will see how the god sketched out by the argument of five ways coincides with the God revealed in scripture. It has also been criticised for not proving there is a God, notably by that pseudo-philosopher Kant. Not quite right either, but let us first get to the argument. And, yes, there has been another critique, on top of those two, that the approach is not patristic: but St Thomas is just giving more detail than St John of Damascus in one of the first chapters of De Fide Orthodoxa.
The first and more manifest way is the argument from motion. It is certain, and evident to our senses, that in the world some things are in motion.
Motion is a bad translation, motus havig other conotations than just loco-motion - movement from one place to another place. Change - as a general concept is as accurate. But loco-motion is the most obvious kind of it, and will occupy by way of example the wording of quite a part of the argument.
Now whatever is in motion is put in motion by another, for nothing can be in motion except it is in potentiality to that towards which it is in motion; whereas a thing moves inasmuch as it is in act. For motion is nothing else than the reduction of something from potentiality to actuality.
Nothing else than - that is proof loco-motion or any word suggesting that is too narrow a word to render St Thomas' motus.
But nothing can be reduced from potentiality to actuality, except by something in a state of actuality. Thus that which is actually hot, as fire, makes wood, which is potentially hot, to be actually hot, and thereby moves and changes it.
Note: he is not saying that being hot is the only condition on which anything in the unierse can make wood change from potentially hot (as in not hot but able to become so) to actually hot (as in hot, really): he is saying the act of being hot is one of act that enables something to render something not-yet-hot hot.
Now it is not possible that the same thing should be at once in actuality and potentiality in the same respect, but only in different respects.
For what is actually hot cannot simultaneously be potentially hot; but it is simultaneously potentially cold.
A log of wood is actually cold, potentially hot until put on the fire. When it burns it is actually hot, potentially cold until ceasing to nourish fire or having it nourished by other things. Ashes that remain in place after a day are actually cold. They are not potentially burning as the log was, they are only potentially heatable, as when heated together with sand to make glass.
It is therefore impossible that in the same respect and in the same way a thing should be both mover and moved, i.e. that it should move itself.
Even Baron Munchhausen was pulling up his his pony-tail with his hand and pulled up by his hand with his pony-tail. I e pulling up and pulled up in different respects, not in the same respects. And, yes, St Thomas would have agreed that atheism is like a universe acting like Baron Munchhausen, and that this is a good way to render his "prima via".
Therefore, whatever is in motion must be put in motion by another.
Like ordinary people pulled out of bogs - whether with their arms or pony-tails by someone already outside the bog.
If that by which it is put in motion be itself put in motion, then this also must needs be put in motion by another, and that by another again.
Like being pulled out of the bog with a rope around your chest which is pulling you because pulled by someone else, standing outside the bog.
But this cannot go on to infinity, because then there would be no first mover, and, consequently, no other mover; seeing that subsequent movers move only inasmuch as they are put in motion by the first mover; as the staff moves only because it is put in motion by the hand. Therefore it is necessary to arrive at a first mover, put in motion by no other; and this everyone understands to be God.
Even Hindoo cosmology with earth on four elephants, elephants on top of a turtle, and a turtle swimming do not go on into infinity, just finish the enumeration with "do not be inquisitive" - which according to St Thomas Aquinas (further on, when discussing what infinity and eternity are) is what geometric projections "into infinity" really are.
The second way is from the nature of the efficient cause. In the world of sense we find there is an order of efficient causes.
Time to review the "four causes": formal and material causes are those by which some thing or occurrence is itself. Pulling out of a bog can be thought of as a formal cause, this or that person stuck in it is material for the action. So, if instead of pulling someone out of the bog we push him back to it (a dreadful thing to do) the formal cause of the occurrence is different, if instead of pulling this someone out of the bog we pull someone else out of the bog, the material cause of the occurrece is different. The efficient cause is Aristotelic terminology for thing or person pulling - a rope pulling because pulled would be an efficient cause caused by another efficient cause, also known as an instrumental cause. And a final cause is the motive to want to chat with the person stuck in the bog as opposed to leaving him to his eternal silence.
There is no case known (neither is it, indeed, possible) in which a thing is found to be the efficient cause of itself; for so it would be prior to itself, which is impossible.
Baron Munchhausen being an obvious exception - if you believe how he pulled himself out of the bog.
Now in efficient causes it is not possible to go on to infinity, because in all efficient causes following in order, the first is the cause of the intermediate cause, and the intermediate is the cause of the ultimate cause, whether the intermediate cause be several, or only one. Now to take away the cause is to take away the effect. Therefore, if there be no first cause among efficient causes, there will be no ultimate, nor any intermediate cause. But if in efficient causes it is possible to go on to infinity, there will be no first efficient cause, neither will there be an ultimate effect, nor any intermediate efficient causes; all of which is plainly false. Therefore it is necessary to admit a first efficient cause, to which everyone gives the name of God.
Actually, this argument differs from previous ot very much. First mover = first changer. And first does not mean earliest. First efficient cause = first changer or up-keeper. Which equally does not mean earliest, and which is a bit more general.
The third way is taken from possibility and necessity, and runs thus. We find in nature things that are possible to be and not to be, since they are found to be generated, and to corrupt, and consequently, they are possible to be and not to be.
Man. Grass. Land risng where there was sea, sea drenching where there was land. He is not talking about appearance or disappearance of species, just of individuals at this level.
But it is impossible for these always to exist, for that which is possible not to be at some time is not. Therefore, if everything is possible not to be, then at one time there could have been nothing in existence.
This one is kind of tricky. I think the Latin text has counterpart of "if everything is possible not to exist, then at one time there would have been nothing in existence". The principle is: if any occurrence or non-occurrence is at all possible, in an eternity of time it sooner or later occurs. A never-occurrence during an eternity of time being tantamount to impossibility of occurrence and a never-non-occurrence being tantamount to impossibility of non-occurrence, i e necessity of occurrence in question. Any imprecision of proof would be on another level - an atheist would argue that every single thing would at some time not have existed, but he would add also that the moment when a does not exist coincides with moments when b does exist. But as we shall c this is not what he really means.
Now if this were true, even now there would be nothing in existence, because that which does not exist only begins to exist by something already existing.
Only here does previousness come into the proof at all. The guy who pulls you out of the bog needs to be "already" out of the bog, so to speak. This is also conceded by atheists.
Therefore, if at one time nothing was in existence, it would have been impossible for anything to have begun to exist; and thus even now nothing would be in existence — which is absurd.
Not only because we know the contrary, but indeed, if we only imagined the contrary we must needs exist some way or another in order to imagine that: and the "imagining" would prove the existence of an imaginer. Even Hindoos allow for Maya being a dram of Brahma.
Therefore, not all beings are merely possible, but there must exist something the existence of which is necessary.
Even materialist atheists concede that. They only say that the thing which exists of necessity is "energy" and that energy "can neither be created nor annihilated" i e what St Thomas attributes to God, they attribute to energy. Which - if true - makes the conclusion of St Thomas wrong in terminology, but not in argument and conclusion.
But every necessary thing either has its necessity caused by another, or not. Now it is impossible to go on to infinity in necessary things which have their necessity caused by another, as has been already proved in regard to efficient causes. Therefore we cannot but postulate the existence of some being having of itself its own necessity, and not receiving it from another, but rather causing in others their necessity. This all men speak of as God.
All men excepting materialist atheists, that is.
The fourth way is taken from the gradation to be found in things. Among beings there are some more and some less good, true, noble and the like. But "more" and "less" are predicated of different things, according as they resemble in their different ways something which is the maximum, as a thing is said to be hotter according as it more nearly resembles that which is hottest; so that there is something which is truest, something best, something noblest and, consequently, something which is uttermost being; for those things that are greatest in truth are greatest in being, as it is written in Metaph. ii. Now the maximum in any genus is the cause of all in that genus; as fire, which is the maximum heat, is the cause of all hot things. Therefore there must also be something which is to all beings the cause of their being, goodness, and every other perfection; and this we call God.
Let us take maximum heat - the parallel - first. It is argued that heat being kinetic energy, objects can acquire more ad more of it. Plasmatic state however means there is a limit to how fast atoms can vibrate. So far the argument of St Thomas stands: at least if there is a limit to heat in plasmatic state of matter. A non-finding of such in laboratories does not imply a non-existence of such. On the other end, cold, an absolute zero is known to exist by the fact that things cannot be more still and non-moving than completely so.
Then there is the question whether good and true are real attributes like hot and cold. Nihilists argue that not so. Good and true are illusions. If so, fourth way falls. Let us therefore revise how "good" and "being" are ontologically interchangeable. St Thomas Aquinas does so further on, when talking about the "attributes" of God.
A rock exists more than a sandheap. Why? If you hew one relatively big piece out of the rock, it is no longer the same rock. And because no piece can be added, as far as natural rock is concerned (at least not on levels observable in one mortal life's timespan). A sandheap remains "itself" even if adding more and more sand to it. A plant or a starfish are more existing than the mineral: if you part the mineral either way into two, it will still be a mineral of exactly same type. In starfish and plants, there are angles at which cutting off will result in a lifeless thing that can no longer live at least on one end of cut. And though a tree split from root to crown, a starfish cut along the middle, can become two trees and two starfish, a vertebrate animal has even more unity and being, a being that is lostwhen cut into two. And spirit able to realise this - like the human one - has even more unity than vertebrate animals, it is not of a nature that can be cut into two. The human sprit is cut off the human body by death, but it is not observed in either life or dedath as cut into two. These are the different degrees naturally and generally observable of being. And, obviously, the human spirit is so not in a position to be the maximum of being responsible for the rest, that every philosophy which has taken this seriously has concluded there are spirits above the human one, and - as often as not - a God above these spirits.
A certain evolutionistic idealism says that man's "spirit" - they may be atheistic materialists and refer to spirit all while thinking of it as an epiphenomenon to matter - the so far grandest result of evolution, all the while hoping society will evolve into something really divine.
St Thomas is arguing - agaist that - that the maximum of being and of spirit must already be there, if there is any such thing as reality and spirit.
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.
This argument is being very laboriously attacked by Laplace saying the gouvernance of solar systems come from their initial state of rotating gaz clouds. And by Marxist Darwinists saying the gouvernance of eco-systems and life cycles come from chance and from disappearance of failures.
In the end, no scientific atheist is even taking Kant seriously as saying St Thomas argued wrongly. They are all in fact occupied saying that "first mover" as St Thomas understands it is energy, "first cause" likewise, "first necessary being" likewise. And adding that blind chance can in theory result and can have in fact resulted in what appears to be gouvernance, whereas goodness may be an illusion and whatever is real about it a product of evolution.
So, you got it: God exists. Only now, when you have got that does St Thomas in a final attempt of completing the question, exhaust the objectios he began with:
Reply to Objection 1. As Augustine says (Enchiridion xi): "Since God is the highest good, He would not allow any evil to exist in His works, unless His omnipotence and goodness were such as to bring good even out of evil." This is part of the infinite goodness of God, that He should allow evil to exist, and out of it produce good.
Reply to Objection 2. Since nature works for a determinate end under the direction of a higher agent, whatever is done by nature must needs be traced back to God, as to its first cause. So also whatever is done voluntarily must also be traced back to some higher cause other than human reason or will, since these can change or fail; for all things that are changeable and capable of defect must be traced back to an immovable and self-necessary first principle, as was shown in the body of the Article.