Aristotle, Plato, and Epicurus: Key Philosophical Concepts
Aristotle’s Philosophy
Aristotle posited that substance is anything with its own principle of change and movement. It’s the primary category supporting all forms of being. His theory, often described as holomorphic, explains substance as composed of matter and form. Matter is the unknown, while form defines essence. Aristotle’s ontology critiques Plato’s ideas, citing their inability to explain movement and the problem of explaining their own ideas.
Aristotle viewed humans as substances, a union of matter and form that cannot be separated. He believed the soul is mortal and identified three types: the appetitive soul (for production and survival), the sensitive soul (for capturing external stimuli), and the rational soul (for understanding forms and principles).
According to Aristotle, the human purpose is to achieve happiness, which he equates with wisdom. This is attained through habit and practice, aiming for a balance between excess and deficiency. Happiness, for Aristotle, is the combination of practical wisdom and virtue. He concluded that knowledge is a blend of senses and reason, the soul is the form of the creature, and there is a natural union between soul and body. The soul is mortal, and the soul and body are complementary.
Plato’s Philosophy
Plato presented reality as two distinct levels: the world of ideas and the sensible world. Ideas are perfect, immutable, and eternal, accessible only through reason. The sensible world is an imperfect, mutable, and finite copy of the intelligible world. Plato’s view is dualistic.
His anthropological concept is also dualistic: humans are a composite of body and soul. The soul shares the nature of ideas and is immortal, while the body is not. The soul is the principle of life and can know the world of ideas. Plato proposed three arguments for the soul’s immortality: the theory of reminiscence (innate knowledge), the argument from simplicity (the soul is indivisible), and the argument of opposites (life/death cycle renewal). Plato believed that humans struggle to balance the parts of the soul, with reason needing to control emotions and feelings. He also saw political imbalances in systems like oligarchy and democracy. His proposal was for a balance between reason, emotion, and desire, achieved through self-knowledge.
Plato concluded that knowledge is remembering, the soul has the nature of the world of ideas, the union between soul and body is unnatural, the soul is immortal, and the body is both simple and compound.
Epicurus’s Philosophy
Epicurus proposed a materialist view of reality, composed of atoms and void. He explained particle movement through the vacuum and causal laws, but also acknowledged randomness. This idea was used to defend the freedom of actions. Epicurus’s anthropological concept is monistic: humans are made of atoms, with the soul composed of finer atoms. He believed that humans cannot achieve balance, and the fear of death is irrational because death is the absence of sensation. When we exist, death is not, and when death is, we do not exist.