Proofs for the Existence of God

Unit 9

Ontological Proof• Put forth by Anselm of

Canterbury (1033-1109)• Not addressed to the

atheist – but to God himself

• Anselm intended it as a form of worship that God would find pleasing

• Called ontological proof because ontology, as we have seen, is the study of the nature of being

Ontological Proof

1. It is possible to conceive of a being “than which nothing greater can be conceived”

2. If that being than which nothing greater can be conceived exists only in the mind, then it is not the greatest being that can be conceived (because it is greater to exist than to not exist)

3. Therefore, the possibility of conceive a being than which nothing greater can be conceived entails the logical necessity of the real existence of such a being

4. This being than which nothing greater can be conceived is the being we call God

Ontological Proof

• Confused? Try Descartes’ less-wordy version:1. God, by definition, is that being that is absolutely perfect2. It is more perfect to exist than to not exist (What’s greater,

a chicken patty that exists only in your mind, or one that is sitting tastily on your plate, ready to be cut up and turned into tasty stir-fry?)

3. Therefore to conceive of God, it is necessary to conceive of him existing

4. Therefore, to say, “God does not exist” is to contradict oneself

5. Therefore, the sentence, “God exists” is necessarily true

Ontological Proof - CriticismsI shall begin by observing that there is an evident absurdity in pretending to demonstrate a matter of fact, or to prove it by any arguments a priori. Nothing is demonstrable unless the contrary implies a contradiction. Whatever we conceive as existent, we can also conceive as non-existent. There is no being, therefore, whose non-existence implies a contradiction. Consequently there is no being whose existence is demonstrable. I propose this argument as entirely decisive and am willing to rest the whole controversy upon it.

---David Hume, Dialogues Concerning Natural Religion

Ontological Proof – Criticisms

• Essentially, Hume asserts that it is illegitimate to move from a pure definition to a statement of fact about reality.

• Definitions pertain to relations between meanings and are purely representative of linguistic conventions

• Statements of fact are based on observation

• Hume concludes that because Anselm’s proof moves from the purely ideological sphere without any reference to observation, its argument must be invalid

• Remember our discussion of Hume as an empiricist and the enormous evidence empiricists place on observation and sense data as the source of knowledge

Ontological Proof - Criticisms

• Is Hume correct?• Perhaps not. Can we never move from the realm of

definition to statements about existence?• How about acute obtuse angles? Do they exist?

» For those who did everything they could do forget geometry, an acute angle is an angle of less than 90 degrees

» An obtuse angle is an angle between 90 and 180 degrees• From these definitions we can deduce that no acute obtuse

angles exist. It would be a logical impossibility. The very definition of an acute angle excludes obtuse angles

• If we can provide even one example where we can move from the realm of definition to the factual realm, Hume’s argument becomes much weaker

Cosmological Proof

• Put forth by Thomas Aquinas (1225-1274)

• Called cosmological because the first premise of this argument makes a reference to an observable fact in the world (cosmos)

• Also called the argument of the “uncaused cause” or the “unmoved mover”

• The term “efficient cause” was borrowed from Aristotle, and is roughly equivalent to what we mean when we say “cause”

Cosmological Proof

• The Argument:1. Every event in the observable world is caused by

some event prior to it2. Either the series of causes is infinite, or the series of

causes go back to a first cause, which is itself uncaused

3. But an infinite series of causes is impossible4. Therefore, a first cause exists outside the observable

world; this first cause is God

Cosmological Proof - Criticisms

• Surprise, surprise – David Hume is not a fan…• As we’ve seen, David Hume is well-known for his

questioning of the concept of “causality”• He says that there is no good reason to believe that

Aquinas’ first premise is true, because it cannot be proven a priori that every event is caused, AND we cannot observe it. Which makes it nonsense in Hume’s book!

Cosmological Proof - Criticisms

• David Hume also takes issue with the third premise, which asserts that an infinite series of causes is impossible. He contends that the requirement for a beginning is only arbitrarily imposed by the human mind

• No matter what event you imagine, you can always imagine an earlier event

• Therefore, according to Hume, there is no logical contradiction in the notion of an “infinite series of causes.” And because there exists no observable data to support the third premise, Hume concludes that we must remain skeptical of its claims

Cosmological Proof - Criticisms• Don’t count the cosmological proof out yet, however• To quote from your text:

…recent Thomistic scholars have warned that Aquinas’ argument is more complicated than it first appears, and involves both a horizontal system of causes (in which an infinite series of causes cannot be ruled out), and a hierarchical system of dependencies (which, according to Thomas, cannot admit of infinite regress).

---D. Palmer, Does the Center Hold? Pages 167-8

• This is a tricky move, because a refutation of this particular interpretation of the proof would require the critic to reject all of Platonic metaphysics!

Teleological Proof

• Originated with Thomas Aquinas in his Summa Theologica

• Known as the argument from design

• Very popular in the 18th century• Called the teleological proof

because teleological refers to an explanation that pertains to goals or intentions

• From the Greek τέλος , meaning goal or end

• Look to your books for examples of teleological explanations (page 169)

Teleological Proof• Aquinas’ proof says that natural phenomena are such

that they demand a teleological explanation or at least that the totality of natural phenomena taken as a system demands such an explanation; no other kind proves satisfactory

• Example of the watch and the watchmaker: if you were to find a watch in the middle of a field, you would deduce that it must serve a purpose and had been created by a skilled mind to serve that purpose. You would never assume that the myriad gears and cogs had just somehow randomly come together to form the watch

• In summary, Aquinas asserts that the universe is so intricate that is can appear to only have been created for the purposes of an intelligent creator

Teleological Proof - Criticisms• Charles Darwin argued that there is

a difference between the concept of “design” and that of “order”

• He contends that while all that has been designed must have been designed by someone, it doesn’t necessarily follow that all that exhibits order must have also been designed

» Ospreys do not have excellent vision in order to spy fish; rather, they spy fish because they have excellent vision

» The moth does not have spots in order to avoid its enemies; it avoids its enemies because it has spots

Teleological Proof - Criticisms• In a way, Darwin’s criticism of the teleological proof

refers to his principle of ‘survival of the fittest:’ the animals that survive are the ones that happen to have those adaptations best suited for survival. If they are in possession of a mutation that gives them the competitive edge over the rest of their species, it follows that they are the ones who are most likely to survive and flourish, and subsequently reproduce in greater numbers

• If Darwin is correct, then the teleological terminology, “in order to” can be replaced with merely causal terminology, effectively crippling the proof

Teleological Proof - Criticisms

• David Hume also took issue with the teleological proof

• He first challenged the validity of the analogy, watch:watchmaker as world:world creator

• The watch:watchmaker relation is empirical, and can be proven by observation. We can infer the existence of the watchmaker because we have seen watchmakers make watches

• We cannot infer the existence of the world creator, because we’ve never seen him create

» Therefore, the relation world:world creator is not empirical, and the analogy fails

Teleological Proof - Criticisms• Secondly, Hume contends that the aspect of the world that

most often requires the need for a teleological explanation is the organic world – which is much more suited to comparison to a plant than a mechanical watch

• Because we know (empirically) where plants come from, Hume (mischievously, naturally) that the argument from analogy should lead us to conclude the world creator is more like a kind of super turnip than a watchmaker

• A final criticism from Hume is that order in the eye of the beholder – the human mind imposes order on the chaos of nature, and then infers a divine orderer to account for it

• In his criticism of the teleological proof, Hume ultimately questions the very nature of order

Conclusion

• One last note: if we assume that these proofs are logical and true, what kind of a God do they prove? Do they necessarily prove the existence of the Christian God? Could they just as easily be used to prove Zeus? Or Allah? Or a deistic god who created the world and has remained uninvolved?

• It would seem that these proofs don’t necessitate the existence of the Christian God, inasmuch as they prove the existence of any sort of deity

• Would these be a useful tool for evangelism?