"If intentionality is irreducible, then materialism is false. For such an irreducible characteristic has no place in physics as we now perceive physics. The materialist is committed to giving some reductive account of intentionality of the mental. Such an account is not all that easy to give.”
David Armstrong, "Naturalism, Materialism, and First Philosophy," in
Contemporary Materialism: A Reader, ed . Paul K. Moser and J. D. Trout (New York:
Routledge, 1995), p. 57.
HT: Pat Parks