2 March

Analytic/ Synthetic Distinction

• Examples of analytic truths: geometric terms, kinship terms, animal terms (boar, sow, piglet, drift, pork)• True in virtue of meaning?• Relation to definitions?• Synthetic truths: “truth depends on actual facts”

A priori/ A posteriori

• Epistemological distinction• A priori “can be known prior to the experience of facts”

A Priori Knowledge

A priori/ A posteriori

• Epistemological distinction• A priori “can be known prior to the experience of facts” • Examples: analytic truths• Some experience necessary: learning the concepts• Other examples: Cartesian truths• “I exist” true in virtue of meaning?• A priori known vs. knowable: computing sums w/ calculator• A posteriori “can only be known as a result of relevant experiences”

Synthetic A Priori?

• Truth depends on actual facts, not just word meanings/ can be known without investigating actual facts• Examples? “All triangles have interior angles that sum to π radians”?• “The real numbers can’t be paired one-to-one with the integers”?• “The future will resemble the past”?• Universal Grammar?

The Knowledge of Babies

“In a few domains, babies seem to have intuitions that guide their expectations about how important entities in the world (e.g., objects, people) act and interact. For example, babies appear to be born knowing that objects cannot magically appear or disappear, that they cannot pass through each other, and that they cannot move unless contacted by another object. These expectations hold for objects, but not for non-object entities like substances (e.g., liquid, sand).”

--Kristy vanMarle

Explanation 1: “Innate Ideas from God”

• God gives us some knowledge at birth.• Problem: methodological

naturalism.• The problem of epistemological

evil– why doesn’t God give us more or better knowledge?

Explanation 2: “Preconditions of Experience”

• Experience is a product of the “things in themselves” AND the way our mind structures them.• Our mind imposes a Euclidean

space-time structure on experience.• Problem?: space-time isn’t part

of external reality.• Problem: empirically false.

Explanation 3: Evolution

• Just as we are born with various innate physical traits that are the product of evolution, so too are we born with innate mental traits that are the product of evolution.

Explanation 3: Evolution

• Problem: evolution satisfices, doesn’t optimize.• In fact, many innate principles

are only approximately true– consider optical illusions.

Possible Worlds

Necessary vs. Contingent

• Necessary = “could not have been false”• Note on modal auxiliary ‘could have’: personal, physical, metaphsycial• Contingent = “could have been false”• Metaphysical distinction, not epistemological• Cf. “Can believe it’s false” vs. “Can’t believe it’s false”

A Posteriori Necessities

• Things that must be true, but need to be investigated to be known.• Informative identity statements• “Whales are mammals.”• “Lightning is an electrical discharge.”• Necessity of origin: Michael’s parents must have been Lowell and

Wendy Johnson.

Moore’s Open Question Argument

• What is it for an act to be morally good? • Can there be a natural property that is identical to the property of

being morally good?• Suppose there can, call it X.• Then things that are X should obviously (a priori) be morally good,

because X = moral goodness.• But it’s always an open question: “Are the things that are X morally

good?”• So there is no such natural property.

An Argument for Dualism

• What is a conscious experience?• Can conscious experiences be identified with physical states of the

brain?• Suppose seeing red = being in brain state B.• Then it should be a priori that beings that see red are in brain state B.• But I can imagine beings that are in B, but don’t see red (philosophical

zombies, inverted spectrum cases…)• Therefore, seeing red is not the same thing as being in any brain state.

A Priori Contingencies

• Things that could have been false, but can still be known without investigation.• Cartesian truths? “I think”, “I exist”, “I have the idea of God”– are

these the result of experience with the relevant facts? A posteriori certainties??• “Jack the Ripper was a murderer.” “Homer wrote the Iliad.” (Cf.

“Shakespeare wrote Hamlet.”) “Dark energy is responsible for the universe’s expansion.”

Possibility

• A statement is possible if it can be true. • Contingently true OR contingently false OR necessarily true• Not necessarily false. • P is possible = not necessarily not-P• P is necessary = not possibly not-P

Possible Worlds

Some things are not true, but they could have been true.

It could have been true that there were talking donkeys, even though there aren’t actually any talking donkeys.

Possible Worlds

Some philosophers have tried to analyze possibility in terms of possible worlds:

It is possible that P.=

In some possible world, it is true that P.

The Multiverse

Important: some physicists believe our universe is part of a multiverse of universes. This is different from the philosophers notion of possible world.

In particular, physicists are not committed to the claim that in some other universe, donkeys talk.

Possible Worlds

Philosophers who believe in possible worlds disagree about what they are. According to Lewis:• Possible worlds are just as real,

and made out of the same sorts of things as the world we live in.• They are universes that are not

spatially connected to ours, so we cannot go there or change what happens there.

Possible Worlds

Robert Stalnaker, however, thinks that possible worlds are not concrete universes. They are instead a type of uninstantiated property:

Possible worlds are maximally specific ways that our world could have been.

Possible Worlds

Possible worlds are maximally specific ways that our world could have been.

This doesn’t particularly help with analyzing modality.