“Fanaticism is an epidemic disease.”Voltaire · Dicționar filozofic · 1764 · Fanatisme
Fanaticism is not an opinion but an infection: caught by contact, not by argument.
Voltaire chooses the medical metaphor carefully: an epidemic disease is not about one person's character but spreads through contact, takes hold more easily in crowds, and strikes whole communities. The mechanism is emotional contagion: in groups, fear and hatred amplify each other, and critical thinking collapses. History offers examples: waves of persecution or collective panic in which ordinary people, harmless one by one, took part in mass violence.
If fanaticism is an infection, then the cure cannot be individual. You don't argue with a virus. Voltaire's comparison suggests something else: a quarantine for thinking. When you feel a group speeding up your heartbeat and narrowing your doubts, that's the sign of contact. Think of an online chat where everyone demands the same punishment for a stranger. Leave the chat, and the anger fades. Return, and it comes back. The individual is not cured alone; the community decides whether the disease circulates or dies out. What would a civic quarantine look like today, concretely?
Why it matters It helps explain online radicalization or mobs: fanaticism is caught through contact, not arguments.