John Locke's "Essay Concerning Human Understanding" was published in London in 1690 (though printed in late 1689). In this groundbreaking work, Locke challenged the rationalist notion of innate ideas, arguing instead that all knowledge derives from sensory experience. The Essay established the foundation for modern empiricism and influenced key Enlightenment thinkers including David Hume and George Berkeley. Its emphasis on rational inquiry and experiential knowledge helped shape philosophical discourse for centuries to follow.