Charisma, like pornography, is easier to recognize than define. Social scientists have not improved on Max Weber’s attempt, which is so vague as to border on tautology. Charisma is not a matter of intelligence (though intelligence helps) or competence (which often doesn’t). It’s essentially erotic, but it need not involve sex. Its mystery led the early Greeks, who first named it, to view it as a gift of the gods: something that cannot be cultivated but might be conferred by grace. Attempts to describe it often rely on metaphors of light: charismatic people are dazzling, or sparkling, or fiery. In an attempt to get beyond social science or metaphor, leading international thinkers will discuss historical, political, religious, literary, and artistic dimensions of this crucial but elusive concept.