In the Critique of Pure Reason, Kant explains that properly philosophical work concludes with defi nition, produces it as its end, rather than beginning from defi nition in the manner of mathematics. The reason: “philosophical defi nitions are brought about only as expositions of given concepts, but mathematical definitions as constructions of concepts made originally. . . . mathematical definitions themselves make the concept, whereas philosophical defi nitions only explicate it.” I want, contrarily, a defi nition of
sorrow from which philosophy can properly and poetically begin, a defi nition of sorrow that makes its concept and produces philosophy by means of its explication. Not a definition of sorrow for the sake of an ultimate understanding or study of sorrow’s nature, but a sorrow for the sake of the ultimate defi nition of our own. A mathematical definition of sorrow that is philosophically poetic, as it were.
“The Sorrow of Being” (here)