If we cross the fingers, a single object beneath them appears to be two; and yet we do not say that there are two, for sight is more decisive than touch; but if touch were our only sense, our judgment would declare that the single object is two.—ARISTOTLE § 24. =The Problem in General.=—The chapters on the mental elements—sensation, simple image, feeling—have made you acquainted with the _results_ of psychological analysis; it was only occasionally that you were asked to analyse for yourself. Henceforth we shall be dealing with experiences that offer themselves _for_ analysis; with experiences that, however simple they may at first sight appear, turn out on investigation to be complex. We shall thus be following the example of those men who, long centuries ago, tried to bring order into mental phenomena and to establish a science of mind. We have an enormous advantage; for they were working in the dark, and we are working in the light of their discoveries. Still, our procedure will be the same as theirs; and the change of work brings with it certain difficulties that you must realise at the outset and be ready to face. Well begun is half done. First of all, then, your reading henceforth will be more difficult, because you will have to _keep more things in mind_. The analysis even of so comparatively simple a thing as a perception or idea cannot be performed in one breath. A knot in a rope may be beautifully simple, and yet you may spend a week in learning it! Secondly, the examples chosen by the author may not be just the right _examples_ for you; even perceptions and ideas, again, differ a good deal in different minds; and an example that is illuminating to one reader may leave another quite blind. So you must look for your own examples in your own experience. Thirdly, you have now to wrestle with the problem of _meaning_ (p. 26); for all perceptions and ideas, and all our still more complicated experiences, mean something; a perception is always the perception _of_ a tree or a wedding or what not; and an idea too is always the idea _of_ something, whether of the landing of Columbus or of the quarrels of the gods in Homer. You must get clear, then, about the psychology of meaning. Fourthly, these concrete experiences that you are to analyse have a long _history_; and in seeking their nervous correlates we shall be obliged, oftentimes, to go far back, even beyond the individual, to the development of the race. In doing this we do not change the problem of psychology (p. 18), but we enlarge our view of it; a mere reference to the organ of sense or the present condition of the nervous system is no longer enough.