More than any philosopher in history, David Hume laid the groundwork for the skepticism and strict empiricism of the twentieth century. One only has to look ahead to the analytic philosophy of Bertrand Russell, especially in his essay “On Induction,” and the logical positivism of A. J. Ayer in his book Language, Truth, and Logic with its attack on all metaphysics and theology. The reach of David Hume's radical skepticism extended for centuries.

It is not merely that Hume laid the groundwork for empiricisms and skeptical schools of thought to come. His influence is larger. For Hume gave to philosophy an impetus to question any and all statements that could not be substantiated with reason or by exacting tests of experience. He spared no target, be it morality or the follies of organized religion, including statements about God, the soul, and claims about the same.

Berkeley took empiricism in the direction of immaterialism, denying the existance of matter and indeed all objects said to exist independently of thought.