"Celsus, then, is altogether ignorant of the purpose of our writings, and it is therefore upon his own acceptation of them that he casts discredit and not upon their real meaning; whereas if he had reflected on what is appropriate[208] to a soul which is to enjoy an everlasting life, and on the idea which we are to form of its essence and principles, he would not so have ridiculed the entrance of the immortal into a mortal body, which took place, not according to the metempsychosis of Plato, but agreeably to another and higher order of things." The teaching of Origen is not easy to set forth clearly, for he is very reticent about many things, and employs a language to which present-day philosophy cannot always find the key; still, the teaching seems full and complete. It comprises pre-existence and even those special associations of certain human souls with animal souls, which we have just spoken of and which form one of the chief mysteries of metempsychosis. In the following words he explains the existence of souls in previous worlds: "The soul has neither beginning nor end.... "Rational creatures existed undoubtedly from the very beginning in those (ages) which are invisible and eternal. And if this is so, then there has been a descent from a higher to a lower condition on the part not only of those souls who have deserved the change, by the variety of their movements, but also on that of those who, in order to serve the whole world, were brought down from those higher and invisible spheres to these lower and visible ones, although against their will. 'For the creature was made subject to vanity, not willingly, but by reason of him who hath subjected the same in hope' (_Rom._, chap. 8, v. 20); so that both sun and moon and stars and angels might discharge their duly to the world, and to those souls who, on account of their excessive mental defects, stood in need of bodies of a grosser and more solid nature; and for the sake of those for whom this arrangement was necessary, this visible world was also called into being. "This arrangement of things, then, which God afterwards appointed not being understood by some, who failed to perceive that it was owing to preceding causes originating in free will, that this variety of arrangement had been instituted by God, they have concluded that all things in this world are directed either by fortuitous movements or by a necessary fate, and that nothing is in the power of our own will."[209] "Is it not rational that souls should be introduced into bodies, in accordance with their merits and previous deeds, and that those who have used their bodies in doing the utmost possible good should have a right to bodies endowed with qualities superior to the bodies of others?"[210]