To know is one thing, and to know for certain that we know is another. - William James

I know that you, ladies and gentlemen, have a philosophy, each and all of you, and that the most interesting and important thing about you is the way in which it determines the perspective in your several worlds. You know the same of me. And yet I confess to a certain tremor at the audacity of the enterprise which I am about to begin. For the philosophy which is so important in each of us is not a technical matter; it is our more or less dumb sense of what life honestly and deeply means. It is only partly got from books; it is our individual way of just seeing and feeling the total push and pressure of the cosmos.

"I CAN, of course, put myself into the sectarian scientist's attitude, and imagine vividly that the world of sensations and of scientific laws and objects may be all. But whenever I do this, I hear that inward monitor of which W. K. Clifford once wrote, whispering the word "bosh!" Humbug is humbug, even though it bear the scientific name, and the total expression of human experience, as I view it objectively, invincibly urges me beyond the narrow "scientific" bounds."

There are no differences but differences of degree between different degrees of difference and no difference.