I have already mentioned that there are different foundations for our belief in anything. One of the most curious things about epistemology, though, is that some of our beliefs cannot be proved. Many of these are our basic first assumptions about reality.
G.K. Chesterton wrote an essay on this, which I have excerpted below. Under each of his points, I give a summary title. Then at the end I post an addition of my own.
1. Every sane man believes that the world around him and the people in it are real, and not his own delusion or dream. No man starts burning London in the belief that his servant will soon wake him for breakfast. But that I, at any given moment, am not in a dream, is unproved and unprovable. That anything exists except myself is unproved and unprovable.
(Summary: THE WORLD EXISTS, AND AS MORE THAN JUST A DELUSION.)
2. All sane men believe that this world not only exists, but matters. Every man believes there is a sort of obligation on us to interest ourselves in this vision or panorama of life. He would think a man wrong who said, “I did not ask for this farce and it bores me. I am aware that an old lady is being murdered down-stairs, but I am going to sleep.” That there is any such duty to improve the things we did not make is a thing unproved and unprovable.
(Summary: EVENTS MATTER. WE HAVE AN INTEREST IN IMPROVING THINGS.)
3. All sane men believe that there is such a thing as a self, or ego, which is continuous. There is no inch of my brain matter the same as it was ten years ago. But if I have saved a man in battle ten years ago, I am proud; if I have run away, I am ashamed. That there is such a paramount “I” is unproved and unprovable. But it is more than unproved and unprovable; it is definitely disputed by many metaphysicians.
(Summary: THERE IS CONTINUITY OF PERSONHOOD/IDENTITY.)
4. Lastly, most sane men believe, and all sane men in practice assume, that they have a power of choice and responsibility for action.
(Summary: WE HAVE FREE WILL.)
And I add one more to GKC’s list, one that I discovered through a clever little story by Lewis Carroll of Alice in Wonderland fame.
5. Every sane man believes in logic itself.
(Summary: LOGIC IS TRUE.)
These are foundational beliefs that we choose to believe or not believe without any evidence because of their utility.
G. K. Chesterton’s essay Philosophy for the Schoolroom