Test 1 Review

Philosophy

•  Love of Wisdom •  Studies conceptual questions that cannot be

answered solely by an appeal to sense experience (or mathematical calculation).

•  Relies on logic to evaluate the strength of arguments.

Main divisions within Philosophy:

•  Metaphysics and Ontology (the study of what is real or what exists)

•  Epistemology (the study of knowledge)

•  Value Theory (the study of values) •  Logic (the study of reasoning)

Reasoning

•  An Argument – Premises supporting a conclusion

•  What is argued for (the conclusion) is distinct from what is argued from (the premises or assumptions).

–  Inductive (probabilistic) vs. deductive (which

purports to show that the conclusion follows necessarily from the premises).

Kinds of Arguments

Inductive: •  Inductive arguments are

probabilistic. They attempt to show that if the premises are true, then the conclusion is probably true.

Deductive: •  Deductive arguments are

not probabilistic. They attempt to show that if the premises are true, then the conclusion must be true. A successful deductive argument is called a “valid” argument.

Validity

•  In a valid argument, the truth of the premises guarantees the truth of the conclusion. –  I.e., if the premises are all true, then the conclusion

must be true. •  So, an argument can be valid even with false premises

and a false conclusion. What it cannot have is all true premises and a false conclusion.

•  Only deductive arguments strive for validity.

In a reductio ad absurdum argument we begin by assuming the opposite of

what we are trying to prove.

We then derive a contradiction (an “absurdity”) from this assumption to

show that it cannot be true (and so that what we are trying to

prove must be true).

Arguments for God’s Existence

•  Ontological: – Argues that the concept of God entails God’s

existence •  Anselm

•  Cosmological: – Argues for a cause of the universe

•  Aquinas, Clarke

Knowledge

•  A Priori – Claims that can be justified without appeal to sense

experience. •  The Ontological Argument is the only a priori argument

for the existence of God

•  A Posteriori – Claims that can be justified only with (by means

of) an appeal to sense experience. •  The Cosmological Argument

A priori vs. A posteriori •  The distinction is not between

–  what caused you to have the idea, •  but about how

–  how you justify your belief that you know this idea to be true. •  If an appeal to sense experience (or your memory of one) is

necessary to prove that you know something, this is a posteriori knowledge. –  For example, “The sky is blue.

•  If you know something by “pure thinking,” such that no sense experience could possibly undermine this knowledge, this is a priori knowledge. –  For example, “2 + 2 = 4”

Anselm

•  Reasons that the existence of God follows from the concept of a being than which none greater can be conceived. –  Uses a reductio ad absurdum argument

•  Assumes that a being, than which none greater can be conceived, exists only in the understanding.

•  But, since any being which exists only in the understanding would be greater if it existed in reality as well, this being is such that a greater can be conceived.

•  This is a contradiction, and so the assumption must be rejected. •  Therefore, a being than which none greater can be conceived cannot

fail to exist in reality as well in the understanding.

Anselm’s Argument (in a nutshell)

•  Claim: A being than which none greater can be conceived exists necessarily, i.e., its non-existence is impossible, because denying its existence involves a contradiction.

•  Reasoning: To say that a being than which none greater can be conceived exists only in the understanding is to say that it would be greater if it existed in reality as well, which means that it (a being than which none greater can be conceived) is such that I can conceive of a greater being (the being it would be if existed in reality as well). And this is contradictory, and so impossible.

Gaunillo •  Argues that Anselm’s argument applies equally to an

island such that none greater can be conceived as to a being than which none greater can be conceived.

•  This means that if Anselm’s argument works to prove the existence of God, it must also prove the exist of such an island.

•  But such an island does not exist. •  So, Anselm’s argument must not work for God either.

Cosmological Argument •  Begins with a premise, based upon sense experience,

that there are cause/effect relationships in the world. •  Reasons that there must be a first cause. •  Aquinas argued that there must be a first cause, or

else the universe would have had an infinitely long past history, and that it couldn’t have had an infinitely long past history, because then it wouldn’t have had a first cause. –  Aquinas doesn’t take an infinite past seriously, and so his

argument for a first cause begs the question.

Aquinas’s Second Way: •  1. Some things are caused to exist. •  2. Nothing can cause itself to exist. (If

so, it would have to “precede itself.”) •  3. This cannot go on to infinity.

– (His argument for this is on the next slide.)

•  So, there must be a first cause—an uncaused causer.

“This cannot go on to infinity.”

“Such a series of [prior] causes must however stop somewhere…. Now if you eliminate a cause, you also eliminate its effects, so that you cannot have a last cause [or “last effect”] … unless you have a first. Given therefore … no first cause, there would be no intermediate causes either, and no last effect.”

–  i.e., without a first cause, nothing else would have happened, and so nothing would be happening now.

–  But things are happening now. –  So, the series cannot go on to infinity.

Why must the series “stop somewhere?”

•  Aquinas’ Answer: –  Because without a first cause, nothing else would ever

happen •  (but, as we know by experience, things have happened).

•  But what is Aquinas trying to prove?

–  That there must be a first cause of the existence of thing, i.e.,

•  that without a first cause, nothing else would ever have happened!

•  What is wrong here?

Aquinas Begs the Question

•  Aquinas is trying to prove that there must be a “first cause.” –  He argues there must be a first cause because otherwise the

series of causes would to on to infinity. –  He argues the series of causes cannot go on to infinity

because then there would be no first cause.

•  This amounts to arguing that there must be a first cause because otherwise there wouldn’t be first cause.

“A Modern Formulation of the Cosmological Argument”

Samuel Clarke 1675-1729

Clarke’s Cosmological Argument

•  Aquinas didn’t seriously consider the possibility that the universe might have had an infinitely long past history. –  Whether or not it could have is the “question” he

“begged.”

•  Clarke says that even if the universe has existed for eternity, we still need to posit the existence of God to explain the existence of the entire infinite series of causes and effects—that is, of the universe as a whole.

Clarke’s Cosmological Argument:

•  1. Suppose (for reductio) that everything there is is part of an infinite series of dependent things –  (where each and every thing is dependent for its

existence upon the existence of some previous thing, ad infinitum.)

–  that is, suppose that nothing (nothing outside the natural world) caused the world.

Clarke’s Cosmological Argument:

“´ c Æ” means causes “∞” means infinity

“D-n” means Dependent Event

An infinite series of dependent events

∞ .... ´ c Æ D-3´ c Æ D-2´ cÆ D-1´cÆ Now0

Clarke’s Cosmological Argument:

•  2. Then the series as a whole has no cause “from without” (because it is hypothesized to include everything there is), and

•  3. The series as a whole has no cause “from

within” (If it had a cause from within, then that thing would be its own cause, making it a necessary being, violating the assumption).

Clarke’s Cosmological Argument

“´ c Æ” means causes “∞” means infinity

“D-n” means Dependent Event

An infinite series of dependent events:

What caused it?

∞ .... ´ c Æ D-3´ c Æ D-2´ cÆ D-1´cÆ Now0

Clarke’s Cosmological Argument:

•  4. So the whole series is without any cause.

•  5. But this cannot be, and so we must posit the existence of God to explain the existence of this infinite series.

Question:

•  But why must “the series as a whole” –  that is, a series of past events, where each is caused

by a previous past event, which is in turn caused by a previous past event, and so on to infinity-

have a cause or explanation?

•  Can we (must we) explain everything?

Must the whole series have a cause?

•  There is a deep question here about how much we can explain.

•  Within Clarke’s “infinite series,” every individual thing has a cause.

•  Must the series of individual things also have a cause?

Causes and Explanations

•  We want to explain things. •  The Cosmological Argument

“posits” (hypothesizes) the existence of God to explain where the universe (the “cosmos”) came from.

•  But how much can we explain?

Clarke’s Cosmological Argument

“´ c Æ” means causes “∞” means infinity

“D-n” means Dependent Event

An infinite series of dependent events:

What caused it?

∞ .... ´ c Æ D-3´ c Æ D-2´ cÆ D-1´cÆ Now0

How much can we explain?

•  If every fact must have an explanation, where can we stop? –  If we need God as an explanation of the infinite series,

don’t we need an explanation of God? –  If some things (like God) don’t need an explanation,

why does the infinite series need an explanation? •  Which is harder to accept?

–  That some facts cannot, even in principle, ever be explained; or

–  That there must be some single being that explains everything, including itself?

What about God?

•  To explain the existence of the entire series of things and events, Clarke argues –  we must assume the existence of God.

•  But … –  If we must explain the existence of everything, mustn’t we

also explain the existence of God? –  If we don’t have to explain the existence of God, why

should we have to explain the existence of an infinite series of things and events?

Swinburne: The Problem of Evil

The Problem of Evil:

•  An all-powerful being would be able to prevent evil from happening in the world.

•  An all-good being would want to prevent evil from happening in the world.

•  Evil happens in the world. •  Therefore, it must not be the case that any

being is both all-powerful and all-good.

“Absence of Good” vs. “Positive Evil”

•  The problem of evil, many theists say, concerns not the lack of perfect goodness in the world, but only the presence of real badness (“positive bad states”).

•  The theist can admit that the world could be better in many ways. God, for the theist, is the source of all goodness, but is not obligated to create all the goodness she could have. So, the lack of perfect goodness in the world is not evidence against the existence of an all good and all powerful being.

Positive Badness (Real Evil)

•  It is only the existence in the world of “positive evil” that the theist must explain. – These explanations, recall, are called

“theodicies.” •  Swinburne divides “positive badness” into

to categories, and offers a different theodicy (explanation) for each. They are: – Moral Evil, and – Natural Evil

Swinburne’s Theodicy: Distinguishes moral evil from natural evil.

•  Moral evil is caused by human beings, and is the inevitable result of the fact that human beings have a free will. (The “Free Will Defense.”)

•  Natural evil is not caused by human beings, but is necessary so that human beings can use their free will to overcome such evil, and so become better people.

•  He thinks this also applies to animal suffering.

Swinburne’s Theodicy

•  “Moral Evil” is caused by human freewill, not by God. – So, the “badness” humans cause is “outweighed”

by the goodness of our having free will. •  “Natural Evil” is created by God because it is

needed in order for us to achieve a greater amount of goodness. – So, again, it’s “badness” is outweighed by a

greater goodness.