chooses; for the reality of the mountain being independent of the notion of the mountain, the notion may also be independent of the reality, and, for anything that can be shown to the contrary, may have been induced by some other cause. In short, the notion, even when the mountain appears present before us, may possibly exist without any corresponding reality, for it clearly does not create that reality.
In looking out, then, for a sure and certain foundation for science, we must not build upon any tenet in which a distinction between our thought and its corresponding reality is set forth (as, for example, upon any proposition expressing the real existence of an external world), for here scepticism might assail us, possibly with success; but we must seek for some subject of experience, between the notion of which and the reality of which there is no flaw, distinction, or interval whatsoever. We must seek for some instance in which the thought of a certain reality actually creates that reality; and if we can find such an instance, we shall then possess an inconcussum quid which will resist for ever all the assaults of scepticism.
But no instance of this kind is to be found, as we have seen, by attaching our thoughts to the objects of the universe around us. Our thinking them does not make them realities. If they are realities, they are not so in consequence of our thoughts; and if they are not realities, unreal they will remain in
