In David Hume's "Enquiry Concerning Human Understanding," he attempts, by way of empiricism, to uncover the basis for knowledge and reasoning. Hume deals with the principle of induction, and his views on synthetic and analytic truths. Take his favorite example: his belief that the sun will rise tomorrow. Clearly, this is a matter of fact; it rests on our conviction that each sunrise is an effect caused by the rotation of the earth. But our belief in that causal relation is based on past observations, and our confidence that it will continue tomorrow cannot be justified by reference to the past. So we have no rational basis for believing that the sun will rise tomorrow. Yet we do believe it. In this essay, I intend to explain his theories of matters of fact and relations of ideas and show how they effect his skepticism concerning induction from past experience to future expectations.

             If we look at the first argument we see that it states, if I can't know the principle of induction to be true, I can't know the sun will rise tomorrow. I can't know the principle of induction to be true. So I can't know the sun will rise tomorrow. Hume argues this by relating it to the explanation in his Sceptical Doubts Concerning the Operations of the Understanding by defining the only two types of knowledge. Relations of ideas and matters of fact. His definition of relations of ideas is that they are the knowledge which is "either intuitively or demonstratively certain"(132). They are universal truths that include mathematics and geometry and do not actually exist in the world except in the form of ideas (132). Matters of fact, on the other hand, require investigation in the real world and are completely uncertain because the contrary of every matter of fact is equally possible and conceivable (132). Hume sets out to discover that which makes us believe any matters of fact that exist beyond what we have observed with our senses in the past or are witnessing in the present.