Chapter VIII. The Same Against the Same, as at Variance With Plato Also in His Theories as to the Heaven: Matters About Which Moses Does Not Concern Himself

‘THEN these are followed by many points in which they are at variance. For the one says that the things in heaven have most of their character from fire, while the other says that the heavenly bodies have nothing to do with fire.[1] And Plato says that God kindled light in the second circle from the earth in order that it might as much as possible illumine the whole heaven, such being his declaration concerning the sun.[2] But the other, not willing that the sun should be fire, and knowing that light is pure fire, or something of fire, does not allow that light is kindled round the sun.

‘Further, the one, attributing formal immortality to all the heavenly bodies, says that there take place certain secretions from them and equivalent accessions; and he is compelled to say this, in regard to the secretions, by the rays of the sun and the heat produced in the efflux from him; and, in regard to the accessions, by the equality in his apparent magnitude: for the bodies would not appear equal if they received nothing in place of what they emit: ‘but Aristotle maintains that they continue altogether the same in substance, without either any secretion from them or any accretion.

‘Further, the one, in addition to the common motion of the heavenly bodies, in which all move in the spheres to which they are confined, both the fixed stars and the planets, gives them another motion also, which indeed happens to be otherwise most admirable, and congenial to the nature of their body; for as they are spherical, naturally each would have a spherical motion of rotation: but the other deprives them of this motion also, which they perform as liviag beings, and leaves them only the motion which results from other bodies surrounding them, as if they were without life.

‘Moreover he says that the appearance presented to us by the stars as if they were in motion is an affection of the feebleness and quivering, as it were, of our sight, and is not a reality: as if Plato derived his belief in their motion from this appearance, and not from the reason which teaches that as each of these is a living being, and has both soul and body, it must necessarily have its own proper motion (for every body whose motion is from without is lifeless, but that which is moved from within and of itself is animated); and when moved, as being divine, it must move with the most beautiful motion, and since motion in a circle is the most beautiful, it must move in this way.

‘And the truth of the sensation would be in part confirmed by the testimony of reason; it was not, however, this sensation that caused the belief in the motion. With regard to the motion of the whole, he could not contradict Plato’s assertion that it takes place in a circle, for he was overpowered by the clear evidence: yet here also this fine invention of the new body gave him room for dissent.

‘For whereas Plato attributed the circular motion to the soul, inasmuch as there were four bodies and all naturally moved in a simple and straight course, fire towards the outside, and earth towards the centre, and the others towards the intervening space, Aristotle, as assigning a different motion to each different body, so also assigned the circular as a sort of bodily motion to his fifth body, easily deceiving himself in all.

‘For to bodies which move in a straight line their heaviness or lightness supplied a source of motion; but the fifth body, partaking neither of heaviness nor lightness, was rather a cause of immobility, and not of motion in a circle.

‘For if to bodies that move in a straight line the cause of their motion is not their shape, but the inclination of their weight, a body, not only when placed in the centre of any like body, will have no inclination in any direction, but, also, when set in a circle round any kind of body whatever, will have no cause of inclination towards anything,

“Move they to right towards the rising sun, Or move to left,” [3]

whether forward or backward.

‘Further, when other bodies have been thrust out of their proper places, the rebound towards these gives them a motion again of themselves; but as that fifth body never departs from its own localities, it ought to remain at rest.

‘And with regard to the other bodies, when this fifth is put out of the question, it is evident that Aristotle out of contentiousness does not agree with Plato. For Plato had inquired whether body, is heavy by nature or light by nature, and, since it was evident that these terms are used according to the relation towards up and down, he had considered whether there is by nature any up and down or not, and had exactly shown that according to the affinities of the bodies to their places, the direction towards which they severally tended would be called “down,” and the other direction from which each would draw back be called “up.” And “heavy” and “light” he disposed according to the same relation, and further proved that neither their centre nor their circumference is rightly called “up” or “down.” But Aristotle makes objection, thinking that he must overthrow the other’s doctrines on every side, and urges us to call that which tends to the centre “heavy,” and that which tends to the circumference “light,” and the place in the centre he calls “down,” and the circumference “up.” ’

Thus widely do they differ from each other in regard to the world, and its constituents, and the heavenly bodies. Such are the opinions of these two. But Moses and the oracles of the Hebrews trouble themselves about none of these things; and with good reason, because it was thought that those who busied themselves about these matters gained no benefit in regard to the right conduct of life.