Aristotle’s Philosophy: Knowledge, Politics, and Ethics

VII. Theory of Knowledge (Epistemology)

Among Greek philosophers, since the Presocratics, senses and experience were undervalued as sources of knowledge. According to Parmenides, the senses provide misleading knowledge (opinion), and only reason allows us to know the truth reliably. Plato thought true knowledge resided solely in Ideas, for which the senses were a constant distraction. However, Aristotle takes the opposite view, restoring empirical value. His theory of knowledge supports an empiricist worldview, emphasizing the world known through our senses. For Aristotle, knowledge cannot exist in the soul prior to its existence in the body. Knowledge is not explained by anamnesis or memory, as Plato suggested, but is acquired throughout life from sensory data.

Knowledge begins with the observation of particulars and rises through abstraction (induction). Abstraction is a complex process of discarding unique, material elements of things, leaving only universal, formal aspects. For example, to understand “table” in general, we abstract from specific tables, disregarding their unique characteristics (height, shape, color, material), and focus on their shared formal aspects. This forms the universal concept of “table,” applicable to all particular tables.

Aristotle identifies different levels of knowledge based on abstraction: feeling (common to humans and animals), perceiving particulars; memory (shared by humans and higher animals), arising from sensations; experience (characteristic of humans), rationally coordinating sensations while remaining aware of specifics (e.g., knowing a plant relieves fever after repeated trials); and understanding (unique to humans), grasping universals (e.g., knowing why a plant relieves fever).

Universal knowledge, or science, leads to necessary and demonstrable knowledge of causes. The hylomorphic doctrine emphasizes the formal cause, enabling knowledge of nature (physis). Science studies universals, essences, and forms. It proceeds inductively from empirical experience to the universal and deductively through syllogisms. Science can be theoretical (First Philosophy, Physics, Mathematics, Theology), practical (Politics, Economics, Ethics), or productive (Grammar, Dialectic, Rhetoric, Poetics, Music, Medicine, etc.).

IX. Politics

According to Aristotle, the ultimate good and happiness depend on a being’s nature. For humans, it is rational activity. Aristotle divides humans into free and slaves by nature. Even among free men, some (farmers, artisans, merchants) are not truly free because they must work. Aristotle also separates men and women; women, having a different nature, are not considered free. Only free men with sufficient means can pursue intellectual activities, virtuous lives, and happiness. Because this is achieved only in the city (polis), Aristotle calls man (free man) a political animal. Only free men are true citizens.

Aristotelian ethics serves politics. The Greeks viewed individuals within society, striving for individual perfection. Ethics and politics seek the good of mankind. While individual interest is desirable, it is more divine when it concerns a people or state. Virtue requires education, which is the state’s responsibility.

VIII. Ethics

Aristotle wrote three ethical treatises: Great Ethics, Eudemian Ethics, and Nicomachean Ethics. The latter most clearly presents his thought. All animals have an ethos—a character defined by tendencies, appetites, and instincts—essential for survival. Aristotle, considered the father of ethology, studies animal behavior. However, humans possess reason and language, expanding possibilities for action and involving deliberation, choice, and rational decision-making. Human ethos requires different treatment, accounting for these factors, which is provided by ethics.

Practical sciences (ethics and politics) focus on human action—a process originating in and impacting humans—distinct from technical production, which results in external objects. Ethics studies actions preceded by deliberation, expressing a person’s character. Deliberation involves reflecting on alternatives before acting. Every action has a purpose, aiming at some good. Ethics deals with the individual’s purpose or aims. Aristotle’s ethics is teleological. Unlike Plato, Aristotle believes in multiple goods and purposes, corresponding to the diversity of beings and actions. Different beings and individuals pursue different goals. The question is the perfect end.

The perfect end is that towards which all other purposes are directed, guiding human life and providing fulfillment. Just as metaphysics identifies substance as the primary category of being, ethics identifies happiness (eudaimonia) as the perfect end. Happiness is sought for itself, while other goods are means to it. Wealth, for example, is sought to acquire necessities, not for itself. Aristotle’s ethics is eudemonistic.

Aristotle rejects wealth, pleasure, and honor as constituents of happiness, as they are not intrinsic to human nature. He argues that happiness relates to the proper function of humans. As rationality distinguishes humans, their end and happiness lie in exercising reason. Happiness is an activity of the soul, according to reason, throughout a full life. However, like a musician’s role is to make good music, humans must not only use reason but cultivate it excellently. Virtue is the habit or stable disposition to exercise reason excellently.