Download
1 / 82
840 likes | 1.1k Vues
Problems for Verificationism. recap. Verificationism. A word or a sentence i s conventionally associated with a set of experiences. Those experiences correlate with certain states of the world: whenever you have those experiences, the world is that way.
E N D
Verificationism • A word or a sentence is conventionally associated with a set of experiences. • Those experiences correlate with certain states of the world: whenever you have those experiences, the world is that way. • The meaning of a sentence is the set of experiences that verify it.
Perfectly correlates with Means “Dagger” Experiences Dagger Mind Experience of a wound
The Elimination of Metaphysics This was part of a radical philosophical agenda, which included “the elimination of metaphysics.” The idea was to view many philosophical problems of the past (and also many religious claims) as meaningless disputes that could simply be ignored.
However, as we will see today, the verificationists are largely thought to have eliminated too much.
Too Little is Meaningless First, one argument that they eliminated too little! The logical empiricists wanted to say that sentences like “The Absolute is Perfect” and “God exists” are meaningless.
Too Little Is Meaningless If you’re of that persuasion, you’re likely to think that “Either some socks are cotton or the Absolute is Perfect” and “Either God exists or snow is purple” are also meaningless. But the latter two clearly have conditions that would verify them.
Too Much Is Meaningless A bigger focus of criticism, however, was that according too the verifiability criterion, too much is meaningless, including: • Statements about the past or future. • Negative existentials. • Positive universals. • Certain positivist doctrines.
Statements about the Past/ Future One objection to the verifiability criterion was that it made statements about the distant past or the distant future meaningless, since there is no way of verifying them.
Statements about the Past “T. Rex had a blue tongue”
Statements about the Future “Hats will be popular among the first humans that colonize Alpha Centauri.”
A Confusion This objection is a little bit confused. Positivists don’t claim that for any meaningful sentence, there actually exists evidence you could find that would (when you found it) confirm that sentence. This would imply that every meaningful sentence was true.
A Confusion To be meaningful, a sentence just has to have verification conditions– it has to be possible for there to be circumstances that verify it.
A Confusion So I could, possibly, verify that T. Rex had a blue tongue by finding a perfectly preserved frozen T. Rex with a blue tongue. Sure, that won’t happen, but that’s not the point. Compare “the Absolute is Perfect”– here, no experience will verify that claim, not even possible experience.
Statements about the Future However, this response only goes so far. What sort of evidence now could conclusively show that hats will be popular on Alpha Centauri?
Reformulation Additionally, we can reformulate the objection. Events outside my light-cone cannot affect me. So in what sense is it even possible to verify “A dinosaur outside my light-cone has a blue tongue”?
Verifiability “In Principle” However, the objection isn’t so simple: complex sentences like this were supposed to be built out of protocol sentences like ‘x is a T. Rex’ and ‘x is blue’ and ‘x is a tongue.’ Each of these has verification conditions. So we can say that a sentence is verifiable in principle if it is a logical construct out of protocol sentences, each of which is verifiable in the old sense.
Russell’s Objection Bertrand Russell pointed out however that some statements that seem meaningful are not verifiable in principle.
Bertrand Russell • 3rd Earl Russell, a British nobleman • Won the Nobel Prize in Literature • Campaigned against war, and even went to jail • Greatly influenced the positivists, but was not a positivist
Russell’s Objection “Neptune existed before it was discovered.”
Russell’s Objection “Atomic war will kill everyone.”
The Verifiability Criterion Itself Consider the verifiability criterion: “a sentence is meaningless unless some finite procedure can conclusively verify its truth.”
The Verifiability Criterion Itself If this criterion is meaningful, then it must be that some finite procedure can conclusively verify the claim that a sentence is meaningless unless some finite procedure can conclusively verify its truth. But what procedure would that be?
Ludwig Wittgenstein • One of the richest people in Europe at the time • Gave away his entire fortune • 3 of his brothers committed suicide • Fought in both World Wars and hid that he was one of the most famous philosophers in the world
Kicking Away the Ladder “My propositions serve as elucidations in the following way: anyone who understands me eventually recognizes them as nonsensical, when he has used them - as steps - to climb beyond them…”
Kicking Away the Ladder “He must, so to speak, throw away the ladder after he has climbed up it.” (Wittgenstein, TractatusLogico-Philosophicus, 6.54)
Existentials and Universals Here’s a(n incomplete) typology of claims: Positive existential: There is an F that is G. Negative existential: There is no F that is G. Positive universal: Every F is G. Negative universal: Not every F is G.
Existentials and Universals Positive existential claims and negative universal claims can be verified by a finite number of experiences. For instance, it suffices to observe just one cow that is dangerous to know that: • There is a cow that is dangerous. • Not every cow is safe.
Existentials and Universals However, negative existentials and positive universals cannot be verified by a finite number of claims. If I observe one billion cows that are dangerous, I still have not shown conclusively: • There is no cow that is safe. • All cows are dangerous.
Negative Existentials Russell tells the following story: “[Wittgenstein] maintained, for example, at one time that all existential propositions are meaningless. This was in a lecture room, and I invited him to consider the proposition: 'There is no hippopotamus in this room at present.' When he refused to believe this, I looked under all the desks without finding one; but he remained unconvinced.”
Falsificationism We might choose to instead identify the meaning of a sentence with its falsification conditions (rather than its verification conditions). These are the circumstances under which it can conclusively be known to be false.
Example: “The House is on Fire” Verification Conditions
Example: “The House is on Fire” Falsification Conditions
Falsificationism This resolves the negative existentials and and positive universals. Observing one safe cow is enough to falsify: • There is no cow that is safe. • All cows are dangerous.
Falsificationism However, this just turns the tables: now we can’t handle positive existentials or negative universals: even observing one billion cows that are safe, I still have not falsified with certainty: • There is a cow that is dangerous. • Not all cows are safe.
Falsificationism too Loose Additionally, since both “The absolute is perfect and some socks are made of cotton” and “Snow is purple and God exists” are falsifiable, they turn out perfectly meaningful for the falsificationist. It seems as though falsificationism is no better off than verificationism.
Would it help to say: New Criterion: A sentence S is only meaningful if one or more of the following is true: • S is a logical truth. • S is verifiable. • S is falsifiable.
All over Some Surprisingly, that would not help. Consider the sentence, “For any substance, there exists a solvent,” and consider some set of observations: • A dissolves X • B dissolves X • C dissolves Y • C dissolves Z
Neither Verifiable Nor Falsifiable No matter how many observations you pile up, the sentence “For any substance, there exists a solvent” will not be verified conclusively. Because there may always be a substance you have not yet considered that does not have a solvent.
Neither Verifiable Nor Falsifiable Furthermore, no set of observations will falsify“For every substance, there exists a solvent,” because even if you have yet to find a solvent for substance S, there may always be one you have not yet considered.
Confirmationism One move to lessen some of the negative implications of verificationismwas to deny that the meaning of a sentence was the conditions under which it was verified (or falsified), and instead identify it with the conditions under which the statement was confirmed (or “infirmed”).
Confirmation The confirmation conditions of a sentence are the set of experiences that, if we had them, would increase the probability that the sentence is true. Unlike verification conditions, confirmation conditions don’t guarantee the truth of the sentence, they just make it more likely.
