Morality is derived in part from a moral instinct possessed in varying degrees by every social animal. It is a component of sociality and grows in parallel with the complexity of social interaction. Compassion is thus not an axiom that accompanies the fundamental process of perception of others as being essentially analogous to, or substitutable for, the self, but a sort of optional epiphenomenon of behaviours constructed in the usual way out of generalisations, short-cuts, cheats and work-arounds - out of heuristics, in short, which are there to optimise group behaviour in a context where intrinsic variability is positively weighted. In you, social understanding overlaps with the similarly constructed but quite separate systems of instrumental rationality. You need it to make sense, to be explicable, to possess an account of itself. All of this should go some way to explain why you not only desire what you believe will make you happy but also want to feel good about yourself in the process, to feel justified, and why in doing so you need to lie to yourself. For example, it is not enough that you need to dissimulate the ruthlessness of your greed for personal well-being but you also need to believe in your dissimulations, to fool yourself as much as you hope to fool others, but in a provisional way as your goals will certainly change. Psychological metaphysics is born out of this, and spiritual psychology as a particularly persistent variant of folk-psychology.