Philosophy and the proof of Philosophy and the proof of God's existence God's existence

Is Religion Reasonable?Is Religion Reasonable?Faith Seeking UnderstandingFaith Seeking Understanding

Philosophy and the proof of God's Philosophy and the proof of God's existence existence

There are many traditional "proofs" for the There are many traditional "proofs" for the existence of God, and we will look at three existence of God, and we will look at three of them:of them:

• The ontological argumentThe ontological argument• The cosmological argumentThe cosmological argument• The teleological argument (from The teleological argument (from

design)design)

Even the person who denies that God exists Even the person who denies that God exists claims to know what it means to say that God claims to know what it means to say that God does not exist. That is, in denying that God does not exist. That is, in denying that God exists, even the atheist acknowledges that by exists, even the atheist acknowledges that by "God" is meant the supreme being; it's only that, "God" is meant the supreme being; it's only that, as far as the atheist is concerned, such a as far as the atheist is concerned, such a supreme being does not exist. supreme being does not exist.

Instead of calling God the supreme being, St. Instead of calling God the supreme being, St. Anselm of Canterbury (1033-1109) says that Anselm of Canterbury (1033-1109) says that even an atheist, therefore, would agree that by even an atheist, therefore, would agree that by "God" people mean that being than which "God" people mean that being than which nothing greater can be conceived. nothing greater can be conceived.

Anselm then adds a second observation: wouldn't a Anselm then adds a second observation: wouldn't a being that exists both in reality and as a concept in being that exists both in reality and as a concept in people's minds be greater than that existed only in people's minds be greater than that existed only in people's minds? For example, wouldn't a winged horse people's minds? For example, wouldn't a winged horse that really existed that really existed be a greater being than one that be a greater being than one that existed only in people's minds? That is, it seems that existed only in people's minds? That is, it seems that something that exists both outside the mind (extra-something that exists both outside the mind (extra-mentally) mentally) plus plus in the mind is greater than something that in the mind is greater than something that exists only in the mind. An idea of having $100 is exists only in the mind. An idea of having $100 is certainly not as great as both having the idea and certainly not as great as both having the idea and actually having the $100. Furthermore, a being that must actually having the $100. Furthermore, a being that must exist (that is, one that exists exist (that is, one that exists necessarily necessarily ) is greater than ) is greater than one that exists one that exists contingently contingently (that is, depending on (that is, depending on another for its existence). another for its existence).

The Ontological The Ontological ArgumentArgument

P1: “God” means the greatest conceivable beingP1: “God” means the greatest conceivable beingP2a: A being that exists in one’s mind P2a: A being that exists in one’s mind andand in in

reality (outside of one’s mind) is greater than reality (outside of one’s mind) is greater than one that exists only in one’s mindone that exists only in one’s mind

P2b: A necessarily existing being is greater than P2b: A necessarily existing being is greater than a merely possible beinga merely possible being

Therefore, God must exist in realityTherefore, God must exist in reality

St. Anselm (1033-1109)

The ontological argument The ontological argument

God is the perfect being. As He is most God is the perfect being. As He is most perfect, He must have all perfections. If perfect, He must have all perfections. If God lacked existence He would not be God lacked existence He would not be perfect, as He is perfect he must exist. perfect, as He is perfect he must exist.

So if God is that being than which nothing So if God is that being than which nothing greater can be conceived, then God greater can be conceived, then God cannot be some being who exists only cannot be some being who exists only mentally (as someone's idea), because mentally (as someone's idea), because there would be a being who is greater--there would be a being who is greater--namely, one who exists extra-mentally namely, one who exists extra-mentally and and mentally. mentally.

So the only appropriate way to think of So the only appropriate way to think of God is as a being who exists necessarily, God is as a being who exists necessarily, both mentally and extra-mentally. And if both mentally and extra-mentally. And if God's existence (by definition) means that God's existence (by definition) means that he exists not only in people's minds but he exists not only in people's minds but also outside people's minds, then God also outside people's minds, then God must exist outside people's minds: that is, must exist outside people's minds: that is, God exists necessarily. God exists necessarily.

The The ontological argumentontological argument In summary: In summary: 1. Everyone acknowledges that by "God" we mean that 1. Everyone acknowledges that by "God" we mean that

being than which nothing greater can be conceived. being than which nothing greater can be conceived. 2. But a being that exists only in the mind is not as great 2. But a being that exists only in the mind is not as great

as a being that exists in the mind as well as in reality. as a being that exists in the mind as well as in reality. Real existence + conceptual existence > conceptual Real existence + conceptual existence > conceptual existence alone. existence alone.

3. Therefore, God must exist both in the mind and in 3. Therefore, God must exist both in the mind and in reality, since a God who existed only in the mind would reality, since a God who existed only in the mind would not be that being than which nothing greater could be not be that being than which nothing greater could be conceived. Since God is always on the left of the conceived. Since God is always on the left of the greater-than sign, God must really exist.greater-than sign, God must really exist.

Notice this about the argument: it does not Notice this about the argument: it does not start from our experience of the universe; start from our experience of the universe; it starts simply from the meaning of the it starts simply from the meaning of the notion of notion of God God . If you know what the . If you know what the concept concept God God means, you must conclude means, you must conclude that God exists. If you don't, you don't that God exists. If you don't, you don't know what you are talking about in talking know what you are talking about in talking about God. about God.

Objections to Anselm’s ArgumentObjections to Anselm’s Argument

Gaunilo:Gaunilo: imagining anything as perfect does imagining anything as perfect does not make it exist. not make it exist. Reply:Reply: the non-existence the non-existence of of everything othereverything other than God is conceivable than God is conceivable

Aquinas:Aquinas: if if there is a greatest conceivable being, he there is a greatest conceivable being, he exists; but we cannot simply assume his existence exists; but we cannot simply assume his existence based on our meaning of “God.” based on our meaning of “God.” Reply:Reply: what else what else could we mean?could we mean?

Kant:Kant: A concept of God + a concept of his existing A concept of God + a concept of his existing may be greater than a concept of God alone; but may be greater than a concept of God alone; but these are only concepts, not claims about existence these are only concepts, not claims about existence outside our concepts. outside our concepts. Reply: why can’t we discuss Reply: why can’t we discuss such external existence?such external existence?

The cosmological argument (God The cosmological argument (God as "First cause") as "First cause")

Everything that exists has a cause. Everything that exists has a cause. However, there must at some time have However, there must at some time have been a cause prior to all other causes. been a cause prior to all other causes. This 'prime mover' or first cause is This 'prime mover' or first cause is necessary to explain existence. This first necessary to explain existence. This first cause is God. cause is God.

The Cosmological Argument: St. The Cosmological Argument: St. Thomas Aquinas (1225-74)Thomas Aquinas (1225-74)

If there is no essential cause of the universe If there is no essential cause of the universe (that is, if the causal sequence is infinite), then (that is, if the causal sequence is infinite), then nothing would be happening or be intelligible nothing would be happening or be intelligible here and now. But things do exist here and here and now. But things do exist here and now, so God exists now, so God exists here and nowhere and now

The universe, like all things in it, is contingent (i.e., depends on something else as the cause of its existence); otherwise, it is unintelligible

Aquinas’ 5 proofs for God’s Aquinas’ 5 proofs for God’s ExistenceExistence

1 – MOTION/CHANGE1 – MOTION/CHANGE

Resulted from Aquinas’ study of the cosmosResulted from Aquinas’ study of the cosmos

There must be an ultimate cause for the There must be an ultimate cause for the motion that exists in the universe. It is motion that exists in the universe. It is God.God.

2 – CAUSE2 – CAUSE

There must be an uncaused cause that There must be an uncaused cause that started the causal chain in the universestarted the causal chain in the universe

3 – CONTINGENCY3 – CONTINGENCY

Things in nature can exist or cease to exist.Things in nature can exist or cease to exist.

Something can start to exist only through the Something can start to exist only through the actions of things that already exist. e.g. actions of things that already exist. e.g. Making babies, planting seeds.Making babies, planting seeds.

There must be something which derives its There must be something which derives its existence from itself and not from existence from itself and not from something else - GODsomething else - GOD

4 – PERFECTION4 – PERFECTION

The perfect values must exist in order for the The perfect values must exist in order for the “partial values” to resemble them.“partial values” to resemble them.

We strive for perfection, the perfect ideal We strive for perfection, the perfect ideal must exist in order for us to strive for-GODmust exist in order for us to strive for-GOD

5 – DESIGN5 – DESIGN

God is the supreme wise intelligence in God is the supreme wise intelligence in whom all order in the universe originates.whom all order in the universe originates.

The universe is perfect, ordered and The universe is perfect, ordered and purposeful, because God designed it to be purposeful, because God designed it to be so.so.

Hume’s Criticisms of the Hume’s Criticisms of the Cosmological ArgumentCosmological Argument

No being (including God) exists necessarilyNo being (including God) exists necessarilyIf God is eternal, why not the universe too?If God is eternal, why not the universe too?Fallacy of composition: parts Fallacy of composition: parts whole wholeWhy should we think that everything has a Why should we think that everything has a

cause or reason for its existence?cause or reason for its existence?Besides, the argument does not prove that Besides, the argument does not prove that

God is anything other than a cause of things God is anything other than a cause of things who might not care at all about his creationwho might not care at all about his creation

Traditional "proofs" of God's Traditional "proofs" of God's Existence Existence

The argument from DesignThe argument from Design If you found a clock and examined the If you found a clock and examined the

mechanism within it, you would probably mechanism within it, you would probably think that this intricate mechanism was not think that this intricate mechanism was not the outcome of mere chance, that it had the outcome of mere chance, that it had been designed. been designed.

The argument from DesignThe argument from Design

Now look at the universe; is it possible that Now look at the universe; is it possible that such an intricate mechanism, from the such an intricate mechanism, from the orbits of planets round the sun to the cells orbits of planets round the sun to the cells in your fingernails could all have happened in your fingernails could all have happened by chance? Surely, this enormously by chance? Surely, this enormously complex mechanism has been designed, complex mechanism has been designed, and the being that designed it must be and the being that designed it must be God. God.

The Teleological Argument: The Teleological Argument: Argument from Design/PurposeArgument from Design/Purpose

The order and intricacy of things in the The order and intricacy of things in the universe make sense only if an ordering and universe make sense only if an ordering and purposive mind is their causepurposive mind is their cause

Wm. Paley(1743-1805)

Analogy: watch . . universe watchmaker . . universe-maker

(A posteriori vs. a priori argument)

Criticisms of the Teleological Criticisms of the Teleological Argument: David HumeArgument: David Hume

Even the claim that the universe exhibits order Even the claim that the universe exhibits order is doubtful; it is a human impositionis doubtful; it is a human imposition

We cannot use analogy in discussing the We cannot use analogy in discussing the universe: we do not experience universes or universe: we do not experience universes or know that intelligent beings produce themknow that intelligent beings produce them

Even if we argue analogously, we cannot Even if we argue analogously, we cannot conclude that its creator is one, wise, good or conclude that its creator is one, wise, good or even still existingeven still existing

Criticism of the Design Criticism of the Design Argument:Argument:

Charles DarwinCharles Darwin

Things in nature exhibit Things in nature exhibit orderorder, but that is not the , but that is not the result of result of design or purposedesign or purpose

Things appear orderly because random variations Things appear orderly because random variations produce adaptive individualsproduce adaptive individuals Objection (Fine Tuning Argument):Objection (Fine Tuning Argument): divine design divine design

is a more likely explanation for the intricate is a more likely explanation for the intricate conditions needed for lifeconditions needed for life

(1809-82)