And now we may suppose that numerous images present themselves to the mind, which begins to act upon them and to arrange them in various ways. Besides the impression of external objects present with us or just absent from us, we have a dimmer conception of other objects which have disappeared from our immediate recollection and yet continue to exist in us. The mind is full of fancies which are passing to and fro before it. Some feeling or association calls them up, and they are uttered by the lips. This is the first rudimentary imagination, which may be truly described in the language of Hobbes, as 'decaying sense,' an expression which may be applied with equal truth to memory as well. For memory and imagination, though we sometimes oppose them, are nearly allied; the difference between them seems chiefly to lie in the activity of the one compared with the passivity of the other. The sense decaying in memory receives a flash of light or life from imagination. Dreaming is a link of connexion between them; for in dreaming we feebly recollect and also feebly imagine at one and the same time. When reason is asleep the lower part of the mind wanders at will amid the images which have been received from without, the intelligent element retires, and the sensual or sensuous takes its place. And so in the first efforts of imagination reason is latent or set aside; and images, in part disorderly, but also having a unity (however imperfect) of their own, pour like a flood over the mind. And if we could penetrate into the heads of animals we should probably find that their intelligence, or the state of what in them is analogous to our intelligence, is of this nature.