What does it mean that man is a 'social animal? Only that humans need one another in order to define themselves and achieve self-consciousness, in a way that molluscs or earthworms do not. We cannot come to a proper sense of ourselves if there aren't others around to show us what we're like. 'A man can acquire anything in solitude except a character,' wrote Stendhal, suggesting that character has its genesis in the reactions of others to our words and actions. Our selves are fluid and require the contours provided by our neighbours. To feel whole, we need people in the vicinity who know us as well, sometimes better, than we know ourselves.