That which is always moved is eternal; but that which gives motion to something else, and is moved itself by some external cause, when that motion ceases, must necessarily cease to exist. That, therefore, alone, which is self-moved, because it is never forsaken by itself, can never cease to be moved. Besides, it is the beginning and principle of motion to everything else. But whatever is a principle has no beginning, for all things arise from that principle, and it cannot itself owe its rise to anything else; for then it would not be a principle did it proceed from anything else. But if it has no beginning, it never will have any end; for a principle which is once extinguished cannot itself be restored by anything else, nor can it produce anything else from itself, inasmuch as all things must necessarily arise from some first cause. And thus it comes about that the first principle of motion must arise from that thing which is itself moved by itself; and that can neither have a beginning nor an end of its existence, for otherwise the whole heaven and earth would be overset, and all nature would stand still, and not be able to acquire any force by the impulse of which it might be first set in motion. Seeing, then, that it is clear that whatever moves itself is eternal, can there be any doubt that the soul is so? For everything is inanimate which is moved by an external force; but everything which is animate is moved by an interior force, which also belongs to itself. For this is the peculiar nature and power of the soul; and if the soul be the only thing in the whole world which has the power of self-motion, then certainly it never had a beginning, and therefore it is eternal.
Now, should all the lower order of philosophers (for so I think they may be called who dissent from Plato and Socrates and that school) unite their force, they never would be able to explain anything so elegantly as this, nor even to understand how ingeniously this conclusion is drawn. The soul, then, perceives itself to have motion, and at the same time that it gets that perception, it is sensible that it derives that motion from its own power, and not from the agency of another; and it is impossible that it should ever forsake itself. And these premises compel you to allow its eternity, unless you have something to say against them.
Well, then, I appeal to you, if the arguments which prove that there is something divine in the souls of men are not equally strong? But if I could account for the origin of these divine properties, then I might also be able to explain how they might cease to exist; for I think I can account for the manner in which the blood, and bile, and phlegm, and bones, and nerves, and veins, and all the limbs, and the shape of the whole body, were put together and made; ay, and even as to the soul itself, were there nothing more in it than a principle of life, then the life of a man might be put upon the same footing as that of a vine or any other tree, and accounted for as caused by nature; for these things, as we say, live. Besides, if desires and aversions were all that belonged to the soul, it would have them only in common with the beasts. But it has, in the first place, memory, and that, too, so infinite as to recollect an absolute countless number of circumstances, which Plato will have to be a recollection of a former life; for in that book which is inscribed Menon, Socrates asks a child some questions in geometry, with reference to measuring a square; his answers are such as a child would make, and yet the questions are so easy, that while answering them, one by one, he comes to the same point as if he had learned geometry. From whence Socrates would infer that learning is nothing more than recollection, and this topic he explains more accurately in the discourse which he held the very day he died, for he there asserts that anyone, who seeming to be entirely illiterate is yet able to answer a question well that
