A History of Mediaeval Jewish Philosophy

by Isaac Husik

The causes of the various combinations of the elements and the generation and destruction of mineral, plant and animal resulting therefrom, are the motions of the heavenly bodies. These are made of a purer substance than that of the four elements, the ether. This is proven by the fact that the heavenly bodies are not subject to change or destruction. They are all permanent and the only change visible in them is change of place. But even their motions are different from those of the four elements. The latter are in a straight line toward the centre or away from it, whereas the heavenly bodies move in a circle eternally around the centre. This is another proof that they are not composed of the same material as sublunar bodies.

The heavens consist of transparent spheres, and the stars as well as the planets are set in them and remain fixed. The motions of the heavenly bodies are due to the revolutions of the spheres in which they are set. These spheres are hollow and concentric. The outermost sphere forming the outer limit of the universe (the world is finite according to Aristotle) is studded with the fixed stars and moves from east to west, making a complete revolution in twenty-four hours. This motion is transmitted to the other spheres which carry the planets. Since, however, we notice in the sun, moon and the other planetary bodies motions in the contrary direction in addition to that from east to west, there must be other spheres having the motions apparent to us in the positions of the planets borne by them. Thus a given body like the sun or moon is set in more than one sphere, each of which has its own proper motion, and the star's apparent motion is the resultant of the several motions of its spheres. Without entering into further details concerning these motions, it will be sufficient for us to know that Aristotle counted in all fifty-five spheres. First came the sphere of the fixed stars, then in order the spheres of Saturn, Jupiter, Mars, Mercury, Venus, Sun, Moon.

God himself sets the outer sphere in motion, or rather is the eternal cause of its motion, as the object of its desire; and in the same way each of the other motions has also its proper mover, likewise a pure form or spirit, which moves its sphere in the same incorporeal and unmoved manner as God.

Thus we have in the supra-lunar world pure forms without matter in God and the spirits of the spheres, whereas in the sublunar world matter and form are inseparable. Neither is found separately without the other.

In man's soul, however, or rather in his intellect we find a form which combines in itself the peculiarities of sublunar as well as celestial forms. When in contact with the human body it partakes of the nature of other sublunar forms exhibiting its activity through matter and being inseparable from it. But it is not destroyed with the death of the body. It continues as a separate form after death.

The soul, Aristotle defines as the first entelechy of the body. The term entelechy which sounds outlandish to us may be replaced by the word realization or actualization and is very close in meaning to the Aristotelian use of the word form. The soul then, according to Aristotle, is the realization or actualization or form of the body. The body takes the place of matter in the human composite. It has the composition and the structure which give it the capacity for performing the functions of a human being, as in any other composite, say an axe, the steel is the matter which has the potentiality or capacity of being made into a cutting instrument. Its cutting function is the form of the axe—we might almost say the soul of the axe, if it were not for the circumstance that it cannot do its own cutting; it must be wielded by someone else.

So far then the human soul forms an inseparable unit with the body which it informs. As we do not think of the cutting function of an axe existing apart from the axe, so neither can we conceive of sensation, emotion or memory as existing without a body. In so far as the soul is this it is a material form like the rest, and ceases with the dissolution of the body. But the soul is more than this. It is also a thinking faculty. As such it is not in its essence dependent upon the body or any corporeal organ. It comes from without, having existed before the body, and it will continue to exist after the body is no more. That it is different from the sensitive soul is proven by the fact that the latter is inherent in the physical organ through which it acts, being the form of the body, as we have seen. And hence when an unusually violent stimulus, say a very bright light or a very loud sound, impinges upon the sense organ, the faculty of sight or hearing is injured to such an extent that it cannot thereafter perceive an ordinary sight or sound. But in the rational faculty this is not the case. The more intense the thought occupying the thinking soul, the more capable it becomes of thinking lesser thoughts. To be sure, the reason seems to weaken in old age, but this is due to the weakening of the body with which the soul is connected during life; the soul itself is just as active as ever.

We must, however, distinguish between two aspects of the rational soul, to one of which alone the above statements apply. Thought differs from sensation in that the latter perceives the particular form of the individual thing, whereas the former apprehends the essential nature of the object, that which constitutes it a member of a certain class. The sense of sight perceives a given individual man; thought or reason understands what it is to be a member of the human species. Reason therefore deals with pure form. In man we observe the reason gradually developing from a potential to an actual state. The objects of the sense with the help of the faculties of sensation, memory and imagination act upon the potential intellect of the child, which without them would forever remain a mere capacity without ever being realized. This aspect of the reason then in man, namely, the passive aspect which receives ideas, grows and dies with the body. But there is another aspect of the reason, the active reason which has nothing to do with the body, though it is in some manner resident in it during the life of the latter. This it is which enables the passive intellect to become realized. For the external objects as such are insufficient to endow the rational capacity of the individual with actual ideas, any more than a surface can endow the sense of sight with the sensation of color when there is no light. It is the active intellect which develops the human capacity for thinking and makes it active thought. This alone, the active intellect, is the immortal part of man.

This very imperfect sketch of Aristotle's mode of approach to the ever-living problems of God, the universe and man shows us the wide diversity of his method from that with which the Jews of Biblical and Rabbinic tradition were identified. Greek philosophy must have seemed a revelation to them, and we do not wonder that they became such enthusiastic followers of the Stagirite, feeling as they must have done that his method as well as his results were calculated to enrich their intellectual and spiritual life. Hence the current belief of an original Jewish philosophy borrowed or stolen by the Greeks, and still betraying its traces in the Bible and Talmud was more than welcome to the enlightened spirits of the time. And they worked this unhistorical belief to its breaking point in their Biblical exegesis.

Aristotle, however, was not their only master, though they did not know it. Plotinus in Aristotelian disguise contributed not a little to their conception of God and his relation to the universe. The so-called "Theology of Aristotle"[25] is a Plotinian work, and its Pantheistic point of view is in reality foreign to Aristotle's dualism. But the middle ages were not aware of the origin of this treatise, and so they attributed it to the Stagirite philosopher and proceeded to harmonize it with the rest of his system as they knew it.