To be able to listen—really, wholly passively, self-effacingly listen—without presupposing, classifying, improving, controverting, evaluating, approving or disapproving, without dueling with what is being said, without rehearsing the rebuttal in advance, without free-associating to portions of what is being said so that succeeding portions are not heard at all—such listening is rare.

The Psychology of Science: A Reconnaissance (1966)