Aristotle’s Hylomorphism: Matter, Form, and the Human Soul
Aristotle’s Hylomorphism: Matter, Form, and Substance
Hylomorphism, Aristotle’s approach to the concept of substance, diverges from Plato’s Theory of Ideas, while still acknowledging the reality of universals. Aristotle conceives the universal not as transcendent and separate from the physical world, but as immanent within it. He terms this universal the “form,” which, together with matter, constitutes the substance of the physical world. Hylomorphism, therefore, is the Aristotelian theory that everything is composed of matter and form.
Understanding Prime Matter (Hyle)
Aristotle distinguishes prime matter (hyle) from the matter of physical bodies. Prime matter is:
- The absolutely undetermined substrate in the composition of all physical things.
- Eternal, neither generated nor capable of perishing.
- Incapable of existing independently of form. The simplest existing bodies, according to Aristotle (water, air, earth, and fire), are already composites of matter and form.
- Necessary for change to occur in physical beings.
- Pure potentiality.
- The principle of individuation, distinguishing individual instances of a species defined by its form.
Substantial Form and Accidental Forms
Forms, for Aristotle, are the equivalent of Plato’s Ideas. They are universal, eternal, and constitute the essence of things. However, unlike Ideas, forms are inherent in things and inseparable from matter. While Aristotle generally refers to the composite of matter and form as “substance,” he sometimes uses “substance” to refer to the form itself, calling it “second substance.” This second substance, also termed substantial form, is distinguished from accidental forms, which merely produce non-substantial changes.
The Human Composite: Body and Soul
In living beings, the soul is the form. Different types of souls correspond to different capabilities, leading to Aristotle’s classification of souls:
- Plants possess a vegetative soul, responsible for nutrition, growth, and reproduction.
- Animals have a sensitive soul, enabling sensations, pleasure, pain, and desires that drive specific movements.
- Humans possess a rational soul, which, in addition to the functions of the sensitive soul, is the principle of rational knowledge and free will.
Humans are the result of the union of body and soul, a hylomorphic composite. Unlike Plato, who believed the soul-body union was accidental, Aristotle argues that it is substantial: soul and body unite to form a single substance, the human being. Furthermore, while Plato affirmed the soul’s immortality, Aristotle believed that the soul, including the human soul, is corruptible like the body.