At the bottom of internal phenomena, whatever they are, the analysis pushed to the limit will never discover more than three irreducible notions: belief, desire, and their point of pure application, pure sense. - La croyance et le desire, Tarde (1880).
(Found in Mind that abides: panpsychism in the new millennium, David Skrbina, after a mention by Bruno Latour in last night's lecture.)
Belief and desire! As tempted as I am to reduce these to vectors - simple forces of the internal self, dual forces of the consolidating shady yin and the bright exuberant yang - I will resist, and instead attempt to retain an understanding of belief and desire as the lively, messy, complicated, massive things they are.