Definition of "dianoetic"

The bitter laugh laughs at that which is not good, it is the ethical laugh. The hollow laugh laughs at that which is not true, it is the intellectual laugh. Not good! Not true! Well well. But the mirthless laugh is the dianoetic laugh, down the snout — Haw! — so.

1953, Samuel Beckett, Watt, 1st American edition, New York, N.Y.: Grove Press, published 1959