This paper is a personal and informal ethnography of the subcultures of psychoanalysis and experimental psychology. It is a case study in incommensurability, and was written out of frustration with the incomprehension that each side displays toward the other. The two disciplines shared many common origins, but each now views the other, by and large, with indifference or hostility. I sketch some reasons why their relationship generates discussions, such as those concerning the scientific status of psychoanalysis, that are like trains passing in the dark. I make some tentative suggestions as to why we may always need such different styles of psychology, and for what different goals, and personal and sociological reasons, we have developed them. I make even more tentative suggestions as to what, if anything, we should do about it.