Progress would not have been the rarity it is if the early food had not been the late poison.

Bagehot’s aphorism frames progress as a process of historical replacement: practices, beliefs, or institutions that once nourished a society’s survival (“early food”) can later become harmful (“late poison”) when conditions change. The line suggests that genuine advancement is rare because it requires not only inventing new solutions but also abandoning inherited habits that were once adaptive and therefore deeply entrenched. It also implies a tragic irony: the very strengths that help a community consolidate—discipline, conformity, settled doctrine—can harden into obstacles to later flexibility. Progress, on this view, depends on recognizing when yesterday’s virtues have become today’s vices and having the political and moral courage to revise them.