The Philosophy of Thomas Aquinas: Part 3: Can You Prove God’s Existence?

As mentioned in the last lecture, Thomas presents five ways to argue for the existence of god.  Rather than calling them proofs, Thomas wants these points to lead people to believe that god exists.  Also, since the lecture series is following the Summa Theologiae these are only short summaries of the arguments presented in the Summa Contra Gentiles.  Before looking at Thomas' arguments Prof Kreeft asks the question, why is this an important question?

Why is belief in God important?  To answer that question Prof Kreeft quotes Nietzsche:

Where is [g]od? I shall tell you. We have killed him, you and I . . . But how have we done this? How were we able to drink up the sea? Who gave us the sponge to wipe away the entire horizon? What did we do when we unchained this earth from its sun? Whither is it moving now? Whither are we all moving now? Away from all suns? Are we not plunging continually? Backward, sideward, forward, in all directions? Is there any up or down left? Are we not straying as through an infinite nothing? Do we not feel the breath of empty space? Has it not become colder? Is not night and more night coming on all the while? . . . Who will wipe this blood off us? What water is there for us to clean ourselves? Is not the greatness of this deed too great for us? Must we ourselves become gods simply to seem worthy of it?

And Sartre:

God does not exist and we have to face all the consequences of this. The existentialist is strongly opposed to a certain kind of secular ethics which would like to abolish [g]od with the least possible expense . . . something like this: [g]od is a useless and costly hypothesis; we are discarding it, but meanwhile, in order for there to be an ethics, a society, a civilization, it is essential that certain values be taken seriously and that they be considered as having an a priori existence. It must be obligatory a priori to be honest, not to lie, not to beat your wife, to have children, etc. etc. So we’re going to try a little device which will make it possible to show that values exist all the same, inscribed in a heaven of ideas, though . . . [g]od does not exist . . . 

Without god there's no source of a priori goodness, no foundation for any moral system.

Of the three types of arguments for god, cosmological, experiential (moral), and ontological, all of Thomas's five ways are cosmological arguments because they deal with cosmology, how we see the universe. Thomas rejected St. Anselm’s “ontological argument” which totally makes sense to me.  All five of the ways are approached in basically the same format, they each start with an observation of one of five features of the universe: motion, causality, contingency, imperfection, and order.  Then, after considering the only two answers possible (either there is or isn't and uncaused first cause), it explains how one answer fails to explain the universe.  Then the opposite must be true.  After both sides are considered and one comes out wanting, Thomas adds a tag, "this is what people call 'god.'"  As I countered Prof McGinn's arguments before, Thomas isn't trying to prove the God of the Bible, just make a way towards showing that a god exists and therefore secular humanism is wrong.

Way #1: Motion/Change

This is his longest, partly because Thomas feels it's the most manifest and probably because the others are related to the first so some of the others can be included in this argument.

It is certain and evident to our senses that in the world some things are in motion. Now whatever is in motion is put in motion by another. For motion is nothing else than the reduction of something from potentiality to actuality, and nothing can be reduced from potentiality to actuality except by something in a state of actuality. Thus that which is actually hot, such as fire, makes wood, which is potentially hot, to be actually hot, and thereby moves it. Thus whatever is in motion must be put in motion by another.
Now if that by which it is put in motion is itself put in motion, then
this also must be put in motion by another, and that by another again. But this cannot go on to infinity, because then there would be no first (unmoved) 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.

The "first mover" can't be the universe itself, because neither a thing in itself can't move itself nor can the complete chain of events start itself.  Like a chain of dominoes, someone has to push the first one, no matter how complex the chain is.

Everything in the material universe needs some kind of explanation.  Even miracles need a sufficient reason, and that reason is a miracle maker.  He uses the example of a rabbit...  If a rabbit suddenly appeared on your desk, you'd immediately start looking for a reason.  Did it fall from the ceiling, jump up from the floor, magician pull it from a hat, or God just create a rabbit on your desk?  There has to be a reason for its existence.

Way #2: Existence

In the world of sense we find that there is an order of efficient causes. There is no case known, nor is it possible, in which a thing is found to be the efficient cause of itself; for if so, it would be prior to itself, which is impossible.
Now in efficient causes following in order, the first is the cause of the intermediate cause, and the intermediate cause is the cause of the ultimate cause, whether the intermediate cause be several or one only. 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, either 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.

 Prof Kreeft's analogy for this one is a book (=existence).

Me: There's a book that explains the entire universe.
You: I'd love to borrow it.
M: Well, I don't have it I have to get it from a friend.
Y: Okay.
M: Well, he doesn't have it, he has to borrow it from the library.
Y: When will that happen?
M: Well, it's not at the library they have to get it from the store.
Y: Is it coming out sometime then?
M: Well, no one really has it...

My children have existence because I gave it to them (in a way, really I just played one small part).  I got my existence from my parents and so on.  The same is true with the entire universe.  Nothing that is created can create itself or else it must have existed before it created itself which is impossible.

Way #3: Contingency

We find in nature things that are able to either be or not be, since they are found to come into existence and go out of existence, and con- sequently they are able to either be or not to be. But it is impossible for any of these beings to exist always, for whatever has a possibility not to be, at some time is not. Thus if everything has the possibility not to be, then at one time there could have been nothing in existence. But if this were true, then there would not be anything in existence now, because that which does not exist cannot begin to exist except by means of something already existing. 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. Therefore not all beings are merely possible but there must exist something whose existence is necessary.

This one is tough.  If there is no god, the universe could have no beginning - infinite.  If the universe is infinite then all contingencies would be possible, including the end of all things.  So, given an infinite amount of time everything ends and if everything ends then the universe would be nothing and it cannot restart itself because nothing comes from nothing.  I've used a similar type argument using entropy, saying that everything is moving from more ordered to less ordered.  Given an infinite universe there should be nothing left.  Also, given that whole galaxies are moving (the so called "red shift") then given an infinite universe they should be an infinite distance away by now.  The so called, god cannot have a beginning, he is a necessary being that has his existence of himself alone.

Way #4: Imperfection

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

. . . so there is something which is truest, something best, something noblest, and consequently something which is uttermost being . . . And this we call God.

This only works if one accepts a ranking of things.  If humans are no better than vegetables, then one that holds that view, would reject this way out of hand.  However, Prof Kreeft quips that if you hold that humans are not better than vegetables, please don't invite him over to dinner.

Way #5: Design

By far his most popular argument I've seen this argument used alone and Prof McGinn treated this as its type of argument for god.

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 by chance but by design do they achieve their end. Now whatever lacks intelligence cannot move toward 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.

Prof Kreeft uses the arrow analogy, the universe is like an arrow flying along a specific trajectory, it's not random everything has a design or an end that is seeks.  And the book analogy, the universe (I'd say most evident is DNA/RNA) is more like a book than an explosion in a print factory.  He brings up a good point, the more design you find the less likely things have happened by chance.  Like a letter 'S' written in the sand, sure wind/waves/the elements could form the letter, but if you find "SOS" you're more certain you're looking for an intelligence, even more so if you find the first page of Hamlet written in the sand.

Prof Kreeft shoots holes in the famous (possibly Bertrand Russell) quote about a million monkeys with a million keyboards for a million years, could type out Shakespeare.  It's possible but no one says that's the explanation of Shakespeare, why would we make the same assumptions about the universe?  Also, Prof Kreeft mentions that a mathematician actually crunched the numbers and said it would take more like a trillion monkeys a trillion years to get just the first paragraph.

One last comment, "intelligent design" scientists claim that irreducible complexity scientifically proves this point.  Prof Kreeft says that he thinks Thomas would not have agreed, that this is a philosophical proof, not a scientific proof.  Prof Kreeft thinks that Thomas would have accepted Darwinian evolution as the design tool that God used to make humans/life as we know it.  As such he wouldn't get the intended insult of the metal bumper emblem of the fish with Darwin's name in it.  He would think it's an argument for theism.  I don't know about this last point and I disagree in general (based mostly on faith/theological interpretation of the Bible, I've written about it before), but that doesn't lessen the impact of the arguments, and I'm sure Francis Collins would agree with these assessments/arguments.

The Philosophy of Thomas Aquinas: Part 2: Philosophy and Theology, Reason and Faith

This lecture greatly appealed to me personally because I feel that this is one of the biggest challenges to faith today, that is the rational relevance and integration of faith in a rational person.  I've written about these topics here and part 2, as well as this entry about the Higgs Boson and this one about Gen 1.  Those are just some samples of how this topic has come up as discussion points, but if you're a regular reader you know that I discuss terms of faith in relation to rational thought all the time.  So, this lecture is all about Thomas' approach to how rational thought works with faith and not against it.

Thomas, as a theologian first, made his life's most important work the Summa Theologiae.  This lecture series is going to, more or less, follow that work's pattern and flow.  To Thomas, there were only three things that were important philosophy, theology, and the scriptures.  His primary goal in writing the Summa is theological education without a loss of logical integrity.  As such Thomas starts off the Summa focusing on God as the origin of everything, then moves on to the creation, mankind.  He focuses on mankind's uniqueness in free will and reason, and mankind's ultimate goal to be reunited (to use Bonhoeffer's terminology) in God's goodness.  I like Prof Kreeft's analogy (I'm not sure if he takes it from the Summa or if it's his own envisioning of the text) of the whole of creation being like a circulatory system with God at the heart and His love as the blood that God pushes out through the body, but then it returns from mankind loving God back.

So, the first question to deal with is the relationship between faith, the source for theology and reason, the source for philosophy.  Thomas sees it as a marriage, a combination of two great sources of knowledge.  Philosophy is based on human reason alone, though there is a branch of theology that relies on human reason, it's called philosophical theology, or natural theology.  Thomas' five ways to prove God's existence fall into this category, it seems to me that apologetics fits this description as well.  There are still parts of theology that are founded on faith, though that's not to say they're irrational beliefs, rather that the point of theology in general is the understanding of God's Word and the Church's interpretation of it throughout history.  Thomas uses both types of theology in his masterwork but there's a distinction between them.

The structure of his work is five parts:
First a question with only two possible answers
Then the opposition's answer summarized fairly, strongly, clearly, and succinctly

Thomas' answer starting with a quotation from authority either human or divine

Then a purely rational argument for the answer

Lastly his answer to why the objections are somewhat right but overall wrong

His first question: Whether, besides philosophy, any further teaching is required?  It may be surprising to know that he answers "yes."  Here's part of a quote about why Thomas says yes, "For man is directed to God as to an end that surpasses the grasp of his reason. But the end must first be known by men who are to direct their thoughts and actions to the end. Hence it was necessary for the salvation of man that certain truths which exceed human reason should be made known to him by divine revelation."  It's awesome to see when great thinkers agree.  Here's a quote from Ravi Zacharias in The End of Reason, "The worldview of the Christian faith is simple enough.  God has put enough into this world to make faith in him a most reasonable thing.  But he has left enough out to make it impossible to live by sheer reason alone."  You can't just use reason, and you can't just rely on faith.

Some might object that this isn't philosophy at all, but that's not how Thomas sees it.  Philosophy is the tool of theology.  And of course that's the intent, this is after all the Summa Theologiae not the Summa Philosophiea.  There are two sets of propositions being dealt with here, truth as perceived by human reason alone and truth received through divine revelation alone.  Both sets are truth and therefore cannot be contradictory.  If there's a contradiction it's not in the sets of truths, rather there is a misunderstanding at some level.  Two sets 'A' and 'B' can be related in five different manners: Some of A is B, Some of B is A, Some of A is B and some B is A, ALL A are B and vice versa, and B is contained within A.  Which is the case with reason and faith.

Some truths are known by faith, the Trinity, while some by reason alone, natural science, and some by both, the existence of God, freedom of the will, and immortality of the soul.  Kant referred to these as the "three fundamental postulates of morality."  Both are truth and truth cannot contradict truth.  Here's a quote from Prof Kreeft about this: "[Thomas held that] religion is not just a set of moral commands or ideals or psychologically helpful and hopeful hints, but a set of propositions that are just as objective as those of science and common sense, though they're known not by the scientific method or by sense observation but by faith."  The second half of the argument is from a Christian perspective that God is the teacher of both reason and faith and God doesn't lie therefore both are true. Therefore, we conclude: "whatever arguments are brought forth against the doctrines of the faith are conclusions that are incorrectly derived from the first and self-evident principles. . . . Such conclusions do not have the force of demonstration; they are arguments that are either only probable or fallacious. And so there exists the possibility to answer them."

Christians can feel comfortable in their intellectual and rational integrity faith and rationality are not mutually exclusive as modern atheist philosophers like to claim (Sam Harris in The End of Faith, and Richard Dawkins in The God Delusion among others).

One final note. St. Bonaventura, one of Thomas' contemporaries, criticised Thomas' use of Aristotle saying that he was diluting "the wine of the Gospel by the water of pagan philosophy."  To which Thomas replied, “No, I am transforming water into wine.”  All reason is the ally of faith because all truth is God’s truth (list of verses about truth here).

Our puppy, Lexie, and her first experience of the beach.  She LOVED it!