Karl Duncker

The degrees of intensity are often more accurately described as degrees of saturation (of an experience with pleasantness) that are characteristic of the experience in question. Lust, for instance, is so highly saturated with pleasantness that is has usurped its very name.

Karl Duncker, ‘On Pleasure, Emotion, and Striving’, Philosophy and Phenomenological Research, vol. 1, no. 4 (June, 1941), p. 408