Nina Strohminger explains why your moral character is the key to your self-identity. “‘Know thyself’ is a flimsy bargain-basement platitude, endlessly recycled but maddeningly empty. It skates the very existential question it pretends to address, the question that obsesses us: what is it to know oneself? The lesson of the identity detector is this: when we dig deep, beneath our memory traces and career ambitions and favourite authors and small talk, we find a constellation of moral capacities. This is what we should cultivate and burnish, if we want people to know who we really are.”