For example, supposing we were to land on an island and an object on the shore attracted our attention, we should try to see what class of things of which we already had experience it most closely resembled. We should observe its movements, and assign it to the class of living creatures; see its four limbs and hair, and conclude it was an animal. Note its upright attitude, clothes, and weapons, and recognise these as characteristic of humanity; but perceiving that its skin differed in colour from that of any human being we had ever seen before, we should partition off a fresh subdivision in the department of our mind in which our ideas connected with humanity were stored, place it there, and probably give it a distinguishing name by means of which we could indicate it to other human beings. Supposing, however, we presently come across another object of the same nature, we should not have to make a fresh subdivision for it, but would classify it with the previously examined specimen, and thus we should feel this time that we “knew what it was.” In fact, the process of “knowing” is a process of classification, and we feel that we “know” a thing when we have assigned it to a satisfactory pigeon-hole among our concepts. CHAPTER IV THE ORGANISATION OF THE UPPER LEVELS OF THE MIND Those untrained in psychology generally conceive of the mind as a homogeneous whole; our first systematic examination reveals to us, however, that the mind is just as organic as the body. The organisation of the mind may best be realised by thinking of it as a tank across which, at different heights, are placed sieves of varying coarseness of mesh. We must conceive of the mind as being composed of certain layers, and the layer in which our conscious life has its most permanent focus we will consider to be the outermost layer and name THE FOCUS OF CONSCIOUSNESS. Immediately behind the Focus of Consciousness lies the level which psychologists call THE FRINGE OF CONSCIOUSNESS, and the two are divided from one another by a sieve-like mechanism which is technically called a CENSOR.