1632–1704 · English philosopher, founder of empiricism
John Locke was an English philosopher whose An Essay Concerning Human Understanding (1689) argued that the mind starts as a blank slate and draws all its ‘materials of reason and knowledge’ from experience. That thesis — empiricism — is the true ancestor of the modern one-liner, though Locke never phrased it as the tidy aphorism now hung on Einstein. Ironically, Einstein himself rejected pure empiricism, insisting that scientific theories are ‘free inventions of the human spirit’ that cannot be derived from experience alone.