He extended the empiricist ideas of Locke and Berkeley. Hume developed a philosophy of radical scepticism. He repudiated the possibility of certain knowledge, maintaining that what we know is based solely on a series of sensations, and that all deductions from experience were the result of habit, not of logical conclusion.

Later he wrote several essays on Moral, Politics and Religion, and a six-volume History of England (1754--62). His views inspired Kant to argue for the inadequacy of empiricism.

Empiricism = knowledge by experience.