Our senses inform us of the existence of the beings with which we are surrounded. These beings exist, or are, quite independently of us. It is true that this is a statement which cannot be proved: for it is one of those first necessary judgements to which we give our assent because of the immediate evidence they themselves furnish. In order to prove the statement we should require a further truth upon which it depended. And no such truth exists in the order which we are now considering. Indeed, from