Hume on Custom and Habit In Hume’s Enquiry Concerning Human Understanding, he claims that it is not reason, but experience which guides and is the basis for most of our beliefs, or matters of fact. What the cause is for this, is the question he ultimately tackles in order to gain an understanding of the human nature of the connection of experience and existence. When discussing how our mind forms connections between various thought, he states that “method and regularity” act to enforce a regular chain of ideas that also serve to relate to memory and imagination (p.14). When this regular chain is broken in upon by some irregular thought, it is quickly noticed. From this, he gathers that because of the regularity that occurs in the thought process, a universal principle exists to bring together ideas in such a comprehensible fashion. These principles of association, as he calls them, are Resemblance, Contiguity, and Cause and Effect. To prove that these three principles hold to connect all possible forms of ideas, he suggests that if all situations are rendered to as general a form as possible, principles of association will apply alone or in some combination in all cases. For our purposes, cause and effect is the most relevant principle which may cast light on Hume’s statement that “Custom, then, is the great guide of human life. It is that principle alone, which renders our experience useful to us,” (p.29). Before entertaining the suggestion that customs are in fact an important guide to human life, it is important to explore the line of reasoning which Hume follows in order to reach this conclusion. Hume, before continuing, looks to consider some skeptical doubts which may bring into question some of the ways by which we believe to have an understanding of ideas. He argues for the usefulness of skepticism, which can excite curiosity though it destroys implicit faith