" The phenomenon of withdrawal is explained by ancient humoral pathology as the dominance of black bile over the three other bodily fluids (blood, mucus, and choler), which is why this type of person was described as melancholic. Bile is manifested in a diffuse lack of will to participate and a generally pervasive low-level alienation. Homo theoreticus seems to suffer from sadness without object: he is not sad about something specific, but marked by feelings of loss without any identifiable reason. For him, it is as if something important were missing in the world. As a result, he will never feel at home—a condition Lamartine invoked in his elegy “Isolement” (Isolation): “Upon the earth in exile why do I remain / As there is nothing more to share between the earth and me. "

― Peter Sloterdijk , The Art of Philosophy: Wisdom as a Practice