A symbolic unity shaped by the sluggishness of the fluids, by the darkening of the animal spirits and the shadowy twilight that they spread over the images of things, by the viscosity of a blood that circulates through the vessels with difficulty, by the thickening of vapours that have blackened, acrid and deleterious, and by the slowed visceral functions, which become bogged down more sensible than conceptual or theoretical, this unity gives melancholy its distinctive formula.