The Kosmos was made a perfect sphere, and with a perfectly smooth outer surface, without organs of sight or hearing, because there was nothing outside to be seen or heard; without organs of respiration, because there was no outside atmosphere to be breathed; and without nutritive or excrementory organs, because it was self-sufficing, being supplied with nourishment by its own decay. It was not furnished with limbs or means of locomotion or standing, because, being a sphere turning on an axis, and having only one of the seven possible varieties of movement, namely, rotation in a circle in one and the same plane, there was nothing for it to grasp or repel.[12] This body, the only-begotten, because in its formation all existing bodily material was employed, perfectly spherical and smooth, equidistant from its center to all points of its circumference, and suspended upon its own axis traversing its diameter, was now to be animated by a soul.

The Demiurgus, in the formation of the soul of the Kosmos, took three constituent ingredients and mixed them together. They were: 1. The Same, or the Identical, the indivisible and unchangeable essence of Ideas; 2. The Different, or the Plural, the divisible essence of bodies or of the elements; 3. A compound of both of these ingredients melted into one. Blended together in one grand compound, these three ingredients formed the soul of the Kosmos by first dividing the mixture into different portions, and then uniting the portions according to a complicated scale of harmonious numerical proportions. The outer or sidereal sphere of the Kosmos was made to receive the Same, or Identity, by being placed in an even and undivided rotation toward the right, turning on the great axis of the whole sphere. The interior, or planetary spheres, the five planets, and the sun and the moon, were made to be under the influence of the Different, or Diversity—that is to say, their rotations on their separate axes, all oblique, were toward the left, while the overpowering force of rotation of the outer sphere carried them along with it, although the time of their separate rotations was more or less modified by their own inherent and countermoving forces.

Thus the sentient capacity of the cosmical soul became the cognition of the Same and the Different, and the blended Same and Different, because it embodied these three ingredients in its own nature. It was invisible; rooted at its center and pervading and inclosing the whole visible body, circulating and communicating, without voice or sound, all impressions and information concerning the existing relations between the separate parts and specialties of the cosmical body.

Anterior to the Kosmos there was no time. With the rotation of the Kosmos time began. It was marked first by the eternal and unchanging rotation of the outer circle, in which were placed the fixed stars, which revolved with it in unaltered position with regard to each other; and one revolution of this outer or most rational circle made a day. The sun, moon, and planets were distributed in different portions of the Circle of the Different; one revolution of the moon marking a month, and one revolution of the sun marking a year. The earth, the first and oldest of the sidereal and planetary gods, was packed around the great axis which ran through the center of the Kosmos, and turned that axis; so that the earth regulated the movement of the great cosmical axis, and was the determining agent of night and day.

Thus far we have the formation of the Kosmos, animated with a pervading soul, the body being formed out of the whole of existing matter, molded into the specific elements of fire, air, earth, and water, and the soul being formed out of the constituent ingredients furnished by the eternal and invisible essence of ideas. The whole, body and soul of the Kosmos, was thus an animal, formed on the abstract but eternal idea or form of an animal which had existed before time began. We now approach the formation of the other animals. Of the Kosmos there could be but one. All existing material of matter had been used in his construction. He could not become a species, as there could be no second Kosmos. Something could be borrowed from him, for the formation of other animals, but nothing could be destroyed. He was not yet, however, a full copy of the model of the Generic Animal or Idea of Animal, because the eternal plan of that model required that he should be peopled or inhabited by four other animals, which might constitute species. Accordingly, the Demiurgus proceeds to form the first of these sub-animals, the gods, who are to inhabit different portions of the Kosmos. The first of these in formation was the earth, planted in the center, and made sentinel over night and day; next the fixed stars, formed chiefly out of fire, and placed in the outer circle of a fixed revolution, or the Circle of the Same, to give to it light and brilliancy. The sidereal orbs thus became animated beings, eternal and divine. They remained constantly turning round in the same relative position, but the sun, moon, and planets, belonging to the Circle of the Different, and trying to revolve by their own effort in a direction opposite to that of the outer sphere, became irregular in their revolutions and varied in their relative positions. Thus the primitive gods were the earth and the fixed stars, which revolved without variation with the Circle of the Same, and became immortal as well as visible; while the sun, moon, and planets were not among the primitive gods, but were simply spherical bodies placed in the inner Circle of the Different. The primitive gods preside over and regulate the Kosmos. From them are generated and descended the remaining gods.[13]

Having completed the Kosmos and the primitive gods, the Demiurgus paused in his work. There were still other animals to be constructed, the first and noblest of which was to be Man. But the Demiurgus, who, in the construction of these gods, had made them immortal, not in their own nature but through his determination, seems to have apprehended that, if he proceeded to construct the other animals himself, they would likewise be thereby rendered of immortal duration. He therefore assembled the newly generated gods and made to them a personal address. He informed them of their immortal existence, and of his purpose to confide to them the construction of the other animals, stating at the same time, in the case of man, that he would himself supply an immortal element which they were to incorporate with a mortal body, in imitation of the power which he had exercised in the generation of themselves. He then proceeded to compound together, but in inferior perfection and purity, the remnant of the same elements out of which he had formed the cosmical soul.[14] He then distributed the whole of this mass into souls equal in number to the fixed stars, placed each of them in a star of its own, where it would be carried round in the cosmical rotation, explained to it its immortal destiny, and that at an appointed hour of birth it would be transferred into a mortal body in conjunction with two inferior kinds of soul or mind. These irrational enemies, the two inferior souls, the rational and immortal soul would have to control and subdue, so as to live a good life. If it triumphed in the conflict, it would return after death to its own star, where in an everlasting abode it would dwell forever in unison with the celestial harmonies and perfections of the outer sphere. But, if it failed, it would be born again into an inferior body, and on the death of that body, if it continued evil, it would be again born into a still more degraded animal, through an indefinite transmigration from animal to animal, until the rational soul should have obtained the mastery over the irrational and turbulent, when it would be released and permitted to return to its own peculiar star.[15] Here, then, the Demiurgus retired, leaving to the gods the work of fabricating mortal bodies for man, and two mortal and inferior souls, with which the immortal soul was to be joined. But before he withdrew he inculcated upon the gods to construct the new mortal animal in the best manner, so that the immortal soul should have the fairest chance of guiding and governing rightly, in order that the animal might not be the cause of mischief and misery to himself; a possible and even probable result which the Demiurgus proclaimed beforehand, thus relieving himself of responsibility, and casting it, it would seem, upon the gods.[16] The latter stood, then, in the position of workmen, who have received certain directions from a superior architect, have been supplied with certain materials, and are obliged to conform to a prescribed model, the cosmical animal, as far as circumstances will allow. The Demiurgus retires, and leaves the gods to their work.

They borrow from the Kosmos, from which they are permitted to obtain materials, portions of the four elements, for the construction of the human body, with an engagement that these materials shall one day be returned. These they unite in one body by numerous minute and invisible fastenings; over this body they place a head or cranium, into which they introduce the immortal soul, making the head, with its spherical form like that of the Kosmos, and admitting of no motion but the rotary, the most divine portion of the human system and master of the body, which is to be subject and ministerial. To the body they give all the six varieties of motive power, forward, backward, upward, downward, to the right and to the left. The phenomena of nutrition and sensation begin as soon as the connection is formed between the immortal soul and the mortal body, but as the irregular movements and agitations arising from the diverse rotations of the Same and the Different convey false and foolish affirmations to the soul in the cranium. That soul is destitute of intelligence when first joined to the body, and remains so for some time. But gradually these disturbing currents abate, the rotations of the Same and the Different in the head become more regular, and the man becomes more intelligent.

It is now necessary to account for the introduction of the two mortal souls, and to show how the conflict appointed for the immortal soul became the test of a life which was to determine whether the latter should be permitted, on the death of the body, to return to its peculiar star, or whether it should be degraded into some lower form of animal. The immortal soul has its special abode in the head, which is both united to and separated from the trunk by the neck. The gods kept the two mortal souls separate, so that the rational or immortal soul might be defiled by the contact as little as possible. The better portion of the mortal soul they placed in the thoracic cavity. It was the energetic, courageous, contentious soul, placed above the diaphragm, so as to receive orders easily from the head, and to aid the rational soul in keeping the mutinous soul of appetite, which was placed below the diaphragm, in subjection.

It is unnecessary to follow here the minute anatomical descriptions which Plato gives of the different organs of the human body, or of the way in which they are supposed to act on the two divisions of the mortal soul, or to be acted on by them, or the mode in which the latter act upon the encephalic or immortal soul which is seated in the cranium. These descriptions evince much knowledge of the human anatomy, and probably all the knowledge that was possessed in Plato's time. It is immaterial how far this anatomical knowledge was correct, and of course there was in Plato's use of the various organs a great deal that was fanciful. It is sufficient, without following Mr. Grote's analysis through these details, to note that, in Plato's arrangement, the immortal soul was supposed to be fastened in the brain, the two mortal souls in the line of the spinal marrow continuous with the brain, and that this line formed the thread of connection between them all.