Upon this Cebes[13] says that he agrees with all else that had been said, but can not help entertaining doubts of what will become of the soul when separated from the body, for the common opinion is that it is dispersed and vanishes like breath or smoke, and no longer exists anywhere. Socrates, therefore, proposes to inquire into the probability of the case, a fit employment for him under his present circumstances. His first argument[14] is drawn from the ancient belief prevalent among men, that souls departing hence exist in Hades, and are produced again from the dead. If this be true, it must follow that our souls are there, for they could not be produced again if they did not exist; and its truth is confirmed by this, that it is a general law of nature that contraries are produced from contraries--the greater from the less, strong from weak, slow from swift, heat from cold, and in like manner life from death, and vice versa. To explain this more clearly, he proceeds to show that what is changed passes from one state to another, and so undergoes three different states--first, the actual state; then the transition; and, thirdly, the new state; as from a state of sleep, by awaking to being awake. In like manner birth is a transition from a state of death to life, and dying from life to death; so that the soul, by the act of dying, only passes to another state. If it were not so, all nature would in time become dead, just as if people did not awake out of sleep all would at last be buried in eternal sleep. Whence the conclusion is that the souls of men are not annihilated by death. Cebes[15] agrees to this reasoning, and adds that he is further convinced, of its truth by calling to mind an argument used by Socrates on former occasions, that knowledge is nothing but reminiscence; and if this is so, the soul must have existed, and had knowledge, before it became united to the body. But in case Simmias should not yet be satisfied, Socrates[16] proceeds to enlarge on this, his second argument, drawn from reminiscence. We daily find that we are carried from the knowledge of one thing to another. Things perceived by the eyes, ears, and other senses bring up the thought of other things; thus the sight of a lyre or a garment reminds us of a friend, and not only are we thus reminded of sensible objects, but of things which are comprehended by the mind alone, and have no sensitive existence. For we have formed in our minds an idea of abstract equality, of the beautiful, the just, the good; in short, of every thing which we say exists without the aid of the senses, for we use them only in the perception of individual things; whence it follows that the mind did not acquire this knowledge in this life, but must have had it before, and therefore the soul must have existed before.