Similarity-Dissimilarity

There never were, in the world, two opinions alike, no more than two hairs, or two grains; the most universal quality is diversity. (Montaigne)

It is by disease that health is pleasant; by evil that good is pleasant; by hunger, satiety; by weariness, rest. (Heraclitus)

Men are created different; they lose their social freedom and their individual autonomy in seeking to become like each other. (David Riesman)