The natural value of egoism. — Self-interest is worth as much as the person who has it: it can be worth a great deal, and it can be unworthy and contemptible. Every individual may be scrutinized to see whether he represents the ascending or the descending line of life. Having made that decision, one has a canon for the worth of his self-interest. If he represents the ascending line, then his worth is indeed extraordinary — and for the sake of life as a whole, which takes a step farther through him, the care for his preservation and for the creation of the best conditions for him may even be extreme. The single one, the “individual,” as hitherto understood by the people and the philosophers alike, is an error after all: he is nothing by himself, no atom, no “link in the chain,” nothing merely inherited from former times; he is the whole single line of humanity up to himself. If he represents the descending development, decay, chronic degeneration, and sickness (sicknesses are, in general, the consequences of decay, not its causes), then he has small worth, and the minimum of decency requires that he take away as little as possible from those who have turned out well. He is merely their parasite.
From Twilight of the Idols (No. 33).