An unsuspicious, generous temperament is a man’s own worst enemy.

Evidence

Evans, since tea, has told me all his troubles and worries. He is a kind, generous, whole-hearted, unsuspicious man, a worse enemy to himself, I believe, than to any other; but I feel sadly that the future of a man who has not stronger principles than he has must be at the best very insecure. — Isabella L. Bird, A Lady’s Life in the Rocky Mountains, 260

Categorization

• APHORISMS: The observation that a man without strong principles faces an insecure future reads as hard-won frontier wisdom about character and self-ruin.
• FICTION: A generous, unguarded man whose openness is the very mechanism of his undoing — a ready-made tragic character type.