If we analyse our perception of any material object, that is to say, of any object which we perceive by means of the senses, we shall find that our perception of the object consists of the sensations which we have of it. To perceive an orange is to see that it is yellow, to feel that it is round, to smell it, taste it, and so on. These various sensations together constitute our perception of the orange. Now, the subjective idealist says that the perception _is_ the orange, and that the orange is the perception. To the beginner in philosophy that sounds absurd: he knows that his perception is not the orange, and that the orange is something more than his perception of it. But when he is asked, "What more? If the orange is not the perception, what is it?" he does not generally produce any satisfactory reply; and then he is told that his notion, that there is anything in the orange except his own perception or sensations, is obviously not a fact of sensation or a thing directly observed, but merely a belief or inference of his. On the other hand, he generally puts a very natural question to his instructor: "If the orange is merely my perception, what becomes of the orange when I do not perceive it? Granted that it exists whenever I look at it, what becomes of it in the intervals when I am not looking at it? Does it exist then, or does it not?" To this Bishop Berkeley replies that it does; that it exists then in exactly the same way as it does now, that is to say, it exists in idea (_i.e._ perception or sensation); but as it does not exist in my perception, when I am not looking at it, it must exist in the perception of some other mind, to which all things at all times are present. With the fact which forms Berkeley's conclusion I have no quarrel. What I should like to show is that it does not follow from these premises. Berkeley's argument is: All men believe, and rightly believe, that the things they see are permanent. The things they see are ideas (perceptions, sensations) of a mind. Therefore the permanent world is the idea of a permanent mind.[5] But "the things they see" is an ambiguous expression. If by "the things that I see" is meant "my sensations of sight," then they are not permanent, for they only last as long as I look at the object, and consequently any argument based on their supposed permanence falls to the ground. On the other hand, if "the things that I see" are permanent, then they are not merely my sensations of sight--in which case subjective idealism is wrong, and my perception of a thing is not the whole account of the thing and does not exhaust its reality. The things which I perceive are not my sensations: they are things of which I have sensations. In fine, they are apprehended, at the moment of apprehension, as being both within and without consciousness.