An overrated objection to Cartesian dualism

A redated post.

William Hasker, who is not a Cartesian dualist, thinks so.

The hoariest objection specifically to Cartesian dualism (but one still frequently taken as decisive) is that, because of the great disparity between mental and physical substances, causal interaction between them is unintelligible and impossible. This argument may well hold the record for overrated objections to major philosophical positions. What is true about it is that we lack any intuitive understanding of the causal relationship between Cartesian souls and bodies. And there is no doubt that, other things being equal, a mind-body theory that allowed such understanding would seem preferable to one that did not. The reason this is not decisive is that, as Hume pointed out, all causal relationships involving physical objects involving physical objects are at bottom conceptually opaque. We find the kinetic theory of gases, with its ping-pong-ball molecules bouncing off each other, fairly readily understandable. This, however, is only because we have learned from experience about the behavior of actual ping-pong balls, and our expectations in such cases have become so habitual that they seem natural to us; we have no ultimate insight into the causal relations except to say, “That’s the way things are.” But equally and emphatically, “the way things are” includes the fact that our thoughts, feelings, and intentions are affected by what happens to our bodies, and vice versa, and to deny these palpable facts for the sake of a philosophical theory seems a strange aberration.

William Hasker, The Emergent Self (Cornell, 1999) p. 130.