Humes influence is evident in the works of quite a lot of other philosophers, among whom are: Adam Smith, Immanuel Kant, Jeremy Bentham, Charles Darwin, and Thomas Henry Huxley. The diverseness of these writers shows what they gleaned from reading Hume; it reflects not only the richness of their sources but also the wide range of Humes empiricism. Contemporary philosophers recognize Hume as one of the most thoroughgoing exponents of philosophical naturalism.
David Hume sought to develop more fully the consequences of Locke's cautious empiricism by applying the scientific methods of observation to a study of human nature itself. He was of the opinion that we cannot rely on the common-sense pronouncements of popular superstition, which illustrate human conduct without offering any illumination, nor can we achieve any genuine progress by means of abstract metaphysical speculation, which imposes a spurious clarity upon profound issues- that we are entirely unjustified in thinking that we can ever know anything about matters of fact. He thought that the alternative is to reject all easy answers; employing the negative results of philosophical skepticism as a legitimate place to start.
Hume felt that since human beings live and function in the world, we should try to observe how they do so. The key principle to be applied to any investigation of our cognitive capacities is, then, an attempt to discover the causes of human belief. According to Hume, the proper goal of philosophy is simply to explain why we believe what we do. His own attempt to achieve that goal was the focus of Book I of his book, the Treatise of Human Nature and all of the first Enquiry.