Ayer, “The Elimination of Metaphysics”

Thesis: Traditional disputes in philosophy are as unwarranted as they are unfruitful.

Main Argument:

P1: Metaphysical claims do not have any factual content.

1a: A claim has factual content only if there is in principle some sensory experience is relevant to its truth value. [Verification Principle]

1b: No possible sensory experience is relevant to the truth value of metaphysical claims.

P2: Metaphysical claims are not logically true/false.

(P3): A claim is cognitively significant only if it either has factual content or is logically true/false.

C: Metaphysical claims are not cognitively significant.

Verification Principle:

A. A claim has factual content only if there is some sensory experience that can establish its truth.

[Counter: “There is life on Alpha Centauri.”]

B. A claim has factual content only if there is in principle some sensory experience that can establish its truth.

[Counter: “All humans are mortal.”]

C. A claim has factual content only if there is in principle some sensory experience that can establish its falsity.

[Counter: “Some human is immortal.”]