Would a logical positivist consider a proposition about objects outside of the earth's light cone to be meaningful?

Question

The logical positivists' basic premise was that for any statement to be meaningful, one had to be able to confirm its truth or falsehood using formal logic and empirical observation. Any statement that cannot be verified with a combination of logic and observation was meaningless. This is called the principle of verification (or verificationism). Thus the statements "There are pandas in China" and "There are green polka dot elephants in China" are both meaningful, although one is true and the other is false. On the other hand, "unicorns are smart" and "horses are cynical" are both meaningless statements.

My question is the following: Would a statement that is otherwise easily verifiable using empirical means, but is located so far away in space, that a light signal from earth could never reach its location in time to test its truth or falsehood be considered meaningful by logical positivists?

Answer 1

The logical positivists hardly subscribed to verificationism, but your question is about verificationism, not about logical positivists, so that's a minor quibble.

Would a statement that is otherwise easily verifiable using empirical means, but is located so far away in space, that a light signal from earth could never reach its location in time to test its truth or falsehood be considered meaningful by logical positivists?

(What does "in time" mean here? According to what time scale?) In any case, the answer is:

Yes, according to verificationism such a statement is meaningful.

To see this we can look at the writings of A.J. Ayer, who after all propagated the kind of verificationism you refer to.

According to Ayer, one must distinguish between "practical verifiability" and "verifiability in principle". And verificationism states that a statement is meaningful if it is verifiable in principle (see Ayer 1952, p. 29).

As Ayer explains:

Plainly we all understand, in many cases believe, propositions which we have not in fact taken steps to verify. Many of these are propositions which we could verify if we took enough trouble. [...] A simple and familiar example of such a proposition is the proposition that there are mountains on the farther side of the moon. No rocket has yet been invented which would enable me to go and look at the farther side of the moon, so that I am unable to decide the matter by actual observation. But I do know what observations would decide it for me, if, as is theoretically conceivable, I were once in a position to make them. And therefore I say that the proposition is verifiable in principle, if not in practice, and is accordingly significant. On the other hand, such a metaphysical pseudo-proposition as “the Absolute enters into, but is itself incapable of, evolution and progress” [a reference to FH Bradley], is not even in principle verifiable. For one cannot conceive of an observation which would enable one to determine whether the Absolute did, or did not, enter into evolution and progress.”

(Ayer 1952, p. 36)

Note that we have seen the "far side" of the moon by now, so the question is verifiable in practice. But you can find many other examples in the literature, such as "There are horses on Alpha Centauri".

You can read more about verificationism and verifiability in principle here:

• Handout by Jeff Speaks on "Ayer on the criterion of verifiability"
• WP: Ayer's Language, Truth and Logic
• A summary of Ayer's Language, Truth and Logic

Reference

Ayer, A. J. (1952). Language, Truth, and Logic. New York: Dover Publications.