Their memory is therefore always dependent upon what is now actually present. Just on this account, however, this excites anew the sensation and the mood which the earlier phenomenon produced. Thus the dog recognises acquaintances, distinguishes friends from enemies, easily finds again the path it has once travelled, the houses it has once visited, and at the sight of a plate or a stick is at once put into the mood associated with them. All kinds of training depend upon the use of this perceptive memory and on the force of habit, which in the case of animals is specially strong. It is therefore just as different from human education as perception is from thinking. We ourselves are in certain cases, in which memory proper refuses us its service, confined to that merely perceptive recollection, and thus we can measure the difference between the two from our own experience. For example, at the sight of a person whom it appears to us we know, although we are not able to remember when or where we saw him; or again, when we visit a place where we once were in early childhood, that is, while our reason was yet undeveloped, and which we have therefore entirely forgotten, and yet feel that the present impression is one which we have already experienced. This is the nature of all the recollections of the brutes. We have only to add that in the case of the most sagacious this merely perceptive memory rises to a certain degree of _phantasy_, which again assists it, and by virtue of which, for example, the image of its absent master floats before the mind of the dog and excites a longing after him, so that when he remains away long it seeks for him everywhere. Its dreams also depend upon this phantasy. The consciousness of the brutes is accordingly a mere succession of presents, none of which, however, exist as future before they appear, nor as past after they have vanished; which is the specific difference of human consciousness. Hence the brutes have infinitely less to _suffer_ than we have, because they know no other pains but those which the _present_ directly brings. But the present is without extension, while the future and the past, which contain most of the causes of our suffering, are widely extended, and to their actual content there is added that which is merely possible, which opens up an unlimited field for desire and aversion. The brutes, on the contrary, undisturbed by these, enjoy quietly and peacefully each present moment, even if it is only bearable. Human beings of very limited capacity perhaps approach them in this. Further, the sufferings which belong _purely_ to the present can only be physical. Indeed the brutes do not properly speaking feel death: they can only know it when it appears, and then they are already no more. Thus then the life of the brute is a continuous present. It lives on without reflection, and exists wholly in the present; even the great majority of men live with very little reflection. Another