A first look at nature shows us the existence of corporeal substances and the universal presence of change. We see that all bodily substances, whether living or not, are subject to generation and corruption. Every change has a starting point and a terminal point. As regards substantial changes, the terminal point is what determines its nature. Aristotle calls this terminal point as the form, understood not in the geometric sense, but as that, which determines the nature of the substance. The substantial form is the reality or perfection produced in any substantial change. Aside from the form, a substrate is also necessary to explain the reality of such changes since “change” implies the change of something into something else; it neither involves the annihilation of the previous substance nor the creation of a new substance from nothing. For example, in the combustion of carbon, ashes are produced. A substrate must exist, common to the starting point and to the term of change. This is not perceived by our senses, but is understood by our intellect. Aristotle calls this substrate prime matter. I quote:
“Therefore, as the saying goes, it is impossible that anything should be produced if there were nothing existing before. Obviously then some part of the result will pre-exist of necessity; for the matter is a part; for this is present in the process and it is this that becomes something” (Aristotle 555).
A relevant topic to this is Plato’s take on the nature of reality. Plato was Aristotle’s teacher and master. However, Aristotle did not subscribe to Plato’s doctrine. Plato says there are two worlds, the world of ideas and the world of sense. Plato claims that it is the world of ideas that is real because it is immutable and eternal. On the other hand, the world of sense is temporary and ever changing, a mere facsimile of the world of ideas. Furthermore, the world of ideas is responsible for whatever occurs in the world of sense. His problem here is to explain how something permanent and unchanging affects another that is temporary and ever changing. To solve the problem, Plato introduces an agent or a divine creator that exists between both worlds. This divine creator takes forms from the world of ideas and introduces these to the world of sense. This doctrine serves as Plato’s philosophical foundation, which Aristotle deviates from.
For Aristotle, everything in the world is made of matter and form. Prime matter and substantial form are not real beings or substances but intrinsic principles of the substance. This means that all sensible realities are composites of matter and form. Moreover, since no matter can exist without a form that determines it, corruption and generation are correlative phenomena: where one is present the other is simultaneously present. Matter and form are intimately related to each other as constitutive principles of material being. This doctrine, which we have explained in a summarized, is known as the hylemorphic doctrine, which is emphasized in book VII, sections 7 - 9, of Aristotle’s Metaphysics. A discussion of this doctrine can also be found in Aristotle’s Physics, book I and book II, sections 1 – 2.
As formulated by Aristotle, the hylemorphic doctrine was an original discovery. Its originality lay in conceiving prime matter as a real potential principle, acting as the determination of an actual perfection. Furthermore, this doctrine is of much importance to Aristotle’s philosophy, for it serves as his foundation for his latter theories. In addition, this view is just as removed from the position of the pre-Socratics – who thought of matter as the only principle of corporeal being, as it is from Plato, who regarded matter as simple and pure privation. As regards the form, Aristotle regarded it as the determining principle of the individual substance; it is the principle of actuality par excellence. The form inheres in the substance and gives it a specific nature. As the act of prime matter, the substantial form determines corporeal being to be what it is; there is therefore only one substantial form in every corporeal being.
Another important element in Aristotle’s philosophy is his doctrine of causes. In book VII, section 8, the principle of causality is given importance as a cardinal point in Aristotelian thought. One of Aristotle’s main criticisms against earlier philosophers is that of not having clearly explained the why of things. It will no do to allege chance and fortuitous events, as some had done; nor will mythological explanations solve the problem. For Aristotle, everything that happens has a cause that explains its origin, its end and the manner of it’s coming to be: “everything that comes to be comes to be by the agency of something and from something and comes to be something” (Aristotle 555), In other words, everything that comes to be is due to a cause.
Aristotle distinguishes four types of causes. Three refer to act, one to potency. Since Aristotle developed his entire theory of causes from the standpoint of being, the basic Aristotelian division of the causes is between an actual cause and a potential cause, and not the traditional division between intrinsic and extrinsic causes made popular by the scholastics. Each of these causes can be briefly defined as follows: a material cause is that out of which something is made. It is the intrinsic constitutive element of something. A formal cause is the form of shape of something; it is what determines its essence to be what it is. An efficient cause is the being in act, which brings about the change. The final cause is that for the sake of which the change takes place; it is what constitutes the perfection of the being. Aristotle regards the final cause as the most important of causes. All the other causes are ultimately founded on the final cause.
Aristotle’s doctrine of causes is scattered in different treatises. The notion of a cause appears in the Posterior Analytics where Aristotle defines science as knowledge through causes. He gives it details treatment, however, in book II of Physics and in the Metaphysics. This clearly shows that the placement of the principle of causality is a cardinal point in Aristotelian thought, with Metaphysics as his most famous work. The placement of his doctrines in the Metaphysics aptly describes the characteristics of this science: “to deal with the first causes and the principles of things” (Aristotle 500), for metaphysics is described as the study of the first causes and ultimate principles of reality.
Aristotle. “Metaphysics.” Trans. W. D. Ross. Great Books of the Western World. Ed. Robert Maynard Hutchins. Vol. 8. Chicago: W. Benton, Encyclopedia Britannica, 1952. Print.