the soul is not the material cause of the body inasmuch as the soul is immaterial. It is not the final cause of the body. And it is not the efficient cause of the body.44 In addition, consider these observations by Gilson:
The notion of soul is much wider than that of a human soul. In its wide sense soul is defined as the first act of an organized body capable of performing the functions of life. Thus, like all form, a soul is an act.45
For St. Thomas, following Aristotle, the soul does not first make a body move, it first makes it a body. A corpse is not a body. The soul makes it exist as a body. It is the soul which assembles and organizes what we call today the bio-chemical element...in order to make a living body from them. In this complete sense, the soul is its first act; that is, is what makes it to be.46
...Therefore human knowledge is the operation of a form which, insofar as it is fitted for knowing bodies, is essentially a stranger to all corporeity. Since the human soul performs operations in which the body has no part, it is a form in which the body has no part. To operate by itself it must subsist by itself, because being is the cause of operation, and everything acts according as it is. What subsists by itself is a substance. The human soul, therefore, is an immaterial substance.47
...The rational soul, as a substance, is not affected by the corruption of the body. Indeed the body only exists by the soul whereas the soul does not exist by the body.48
...That by which a being passes from potency to act is, indeed, the proper form and the act of this being. Now the living body is only alive in potency until the soul has come to inform it. Only while it is vivified and animated by its soul does the human body really deserve its name. The eye or the arm of a corpse is no more a real eye or arm than if painted on canvas or sculptured in stone. It is the soul that places the body into the species of human body. It is the soul that confers upon it in act the being it possesses. The soul, then, is really its form as we have supposed. Not only can we deduce this conclusion from a consideration of the human body which the soul animates and vivifies, but also from the definition of the human species. When we wish to find out the nature of a being, we have only to determine what its operation is. Now the proper operation of man, considered as man, is intellectual knowledge. Through it he surpasses in dignity all the other animals. It is for this reason that Aristotle places man’s sovereign happiness in this characteristic operation. Hence it is this principle of intellectual operation which puts man in the species in which he finds himself. But the species of a being is always determined by its proper form. Therefore the intellective principle, that is, the human soul, is the proper form of man.49
More recently, Pope John Paul II referred50 to
the Church's teachings on the unity of the human person, whose rational soul is per se et essentialiter [through itself and essentially] the form of his body. The spiritual and immortal soul is the principle of unity of the human being, whereby it exists as a whole—corpore et anima unus—as a person. These definitions not only point out that the body, which has been promised the resurrection, will also share in glory. They also remind us that the reason and free will are linked with all the bodily and sense faculties. The person, including the body, is completely entrusted to himself, and it is in the unity of body and soul that the person is the subject of his own moral acts. The person, by the light of reason and the support of virtue, discovers in the body the anticipatory signs, the expression and the promise of the gift of self.51
The soul, the formal cause of the body, can exist without the body, though it does not preexist the body; but the body cannot exist without the soul. As the ground for the body, the soul makes the body human; it gives the body life. Accordingly, there are two states of the same soul/substance:
it is insofar as it is an intellect that the human soul is an immaterial substance. However, remembering that the intellectual operation presupposes sensation and demands the collaboration of the body, St. Thomas says without hesitation that the intellect is the form of the human body: “We must assert that the intellect which is the principle of intellectual operation is the form of the human body.”52
And there are two forms of common sense, one relating to the exterior experience of the body and one relating to the body’s interior experience. The respective sciences are Grammar and Rhetoric.
Now, the medieval pattern of four senses of Scripture has its ancestry in a classical doctrine of philology that precedes Christianity, namely the four levels of exegesis of literature and of the Book of Nature, including man and society. Varro explains the four levels as follows:
Now I shall set forth the origins of the individual words, of which there are four levels of explanation. The lowest is that to which even the common folk has come.... The second is that to which old-time grammar has mounted, which shows how the poet has made each word which he has fashioned and derived..
The third level is that to which philosophy ascended and on arrival began to reveal the nature of those words which are in common use... The fourth is that where the sanctuary is, and the mysteries of the high-priest: if I shall not arrive at full understanding there, at any rate I shall cast about for a conjecture.53
While the multi-levelled exegesis of Scripture has been practiced continuously from the earliest days of the church to the present, such “polysemous” compositions and interpretations among poets and critics have been relatively sporadic. Yet they have not died out but continue, even in our time. Dante Alighieri and T. S. Eliot are two of the better-known practitioners.
Throughout the Middle ages, study of secular literature was cultivated in order to provide a training ground for the interpretation of scriptural texts. Interpretive skills were practiced first on Homer and Virgil and the poets, and then were applied to the Scriptures. But poets’ use of the four senses of exegesis did not end with the advent of christianity. Dante, a conspicuous example, composed his Commedia with polysemous interpretation in mind, as he explains in the celebrated Letter to Lord Can Grande della Scala:
For the clarification of what I am going to say, then, it should be understood that there is not just a single sense in this work: it might rather be called polysemous, that is, having several senses. For the first sense is that which is contained in the letter, while there is another which is contained in what is signified by the letter. The first is called literal, while the second is called allegorical, or moral or anagogical. And in order to make this manner of treatment clear, it can be applied to the following verses: “When Israel went out of Egypt, the house of Jacob from a barbarous people, Judea was made his sanctuary, Israel his dominion.”54 Now if we look at the letter alone, what is signified to us is the departure of the sons of Israel from Egypt during the time of Moses; if at the allegory, what is signified to us is our redemption through Christ; if at the moral sense, what is signified to us is the conversion of the soul from the sorrow and misery of sin to the state of grace; if at the anagogical, what is signified to us is the departure of the sanctified soul from bondage to the corruption of this world into the freedom of eternal glory. And although these mystical senses are called by various names, they may all be called allegorical, since they are all different from the literal or historical. For allegory is derived from the Greek alleon, which means in Latin alienus (“belonging to another”) or diversus (“different”).
This being established, it is clear that the subject about which these two senses play must also be twofold. And thus it should first be noted what the subject of the work is when taken according to the letter, and then what its subject is when understood allegorically. The subject of the whole work, then, taken literally, is the state of soul after death, understood in a simple sense; for the movement of the whole work turns upon this and about this. If on the other hand the work is taken allegorically, the subject is man, in the exercise of his free will, earning or becoming liable to the rewards or punishments of justice.55
Now
