That whenever the _existence_ of a belief depends to some extent on us, then also the _truth_ of that belief depends to some extent on us; in the sense in which this implies, that, when the existence of my belief that a shower will fall depends upon me, then, if this belief is true, I must have had a hand in making the shower fall: that, therefore, men must have had a hand in making to exist almost every fact which they ever believe to exist. [1] _Pragmatism: A New Name for some Old Ways of Thinking: Popular Lectures on Philosophy._ By William James. Longmans, Green, and Co., 1907 HUME'S PHILOSOPHY In both of his two books on the Human Understanding, Hume had, I think, one main general object. He tells us that it was his object to discover "the extent and force of human understanding," to give us "an exact analysis of its powers and capacity." And we may, I think, express what he meant by this in the following way. He plainly held (as we all do) that some men sometimes entertain opinions which they cannot know to be true. And he wished to point out what characteristics are possessed by those of our opinions which we _can_ know to be true, with a view of persuading us that any opinion which does _not_ possess any of these characteristics is of a kind which we _cannot_ know to be so. He thus tries to lay down certain rules to the effect that the _only_ propositions which we can, any of us, know to be true are of certain definite kinds. It is in this sense, I think, that he tries to define the limits of human understanding.