Aristotle’s Philosophy: Ethics, Causality, and Knowledge

Posted on Nov 26, 2025 in Philosophy and ethics

Aristotelian Ethics: The Pursuit of Eudaimonia

Aristotle addresses ethics in works such as the Nicomachean Ethics and the Eudemian Ethics. For him, the ultimate goal of humanity is the search for the best life possible—the happy life (eudaimonia).

He poses the question: What is happiness, and how is it achieved?

  1. Happiness as a Means: If happiness is merely a means, or dependent on external means, we fall into relativism. Aristotle argues that this view would prevent the establishment of a universal ethic. Faced with this question, individuals would give different answers: money, fame, power, health, etc.
  2. Happiness as an End in Itself: Beings (ousia) must achieve happiness (eudaimonia) by performing the activity proper to them. In humans, this proper activity is contemplation, reflection, and the use of reason.

However, because humans possess physiological and emotional aspects, absolute contemplation (ataraxia) is impossible. Therefore, complete happiness is unattainable. Nevertheless, Aristotle believes it is possible to achieve eudaimonia through **Virtue** (Arete).

Virtue is teachable and enables the suitable form of activity which is proper to us. Aristotle identifies two kinds of virtues:

  1. Intellectual (Dianoetic) Virtues: These develop the intellect (nous). The key intellectual virtue is **Prudence** (phronesis).
  2. Moral (Ethical) Virtues: These focus on the perfection of character, conduct, and ethics.

Key Moral Concepts

  • The Rule of the Mean: A person should act not based on the average behavior of the majority, but for themselves, finding the appropriate middle ground between extremes. (Note: This concept is distinct from the Kantian Golden Rule: “Comport yourself as if your conduct represented a universal law.”)
  • Friendship: Life without friendship is worthless. It is the foundation of society. If all citizens were friends, the city government would be perfect.

According to Aristotle, **Justice** is the epitome (conclusion) of the virtues of rational coordination in the implementation of activity that is proper to us.

Aristotle’s Theory of Causality

According to Aristotle, “All men by nature **desire to know**” (a famous phrase from Book I of the Metaphysics). We only truly know the object of study when we understand the causes that bring it about.

The principle of causality states that every effect is derived, at least, from a previous cause. Aristotle classifies causes into two main categories:

  • Intrinsic (Internal) Causes:
    • Material Cause: That out of which something is made (e.g., marble).
    • Formal Cause: The figure or essence it shows (e.g., the form of the discus thrower).
  • Extrinsic (External) Causes:
    • Efficient Cause (or Agent): Who or what brings the change about?
    • Final or Teleological Cause: Why is it done? (The purpose or end goal).

Aristotelian Epistemology: The Acquisition of Knowledge

According to Aristotle, all men **desire to know**. Knowledge is achieved by understanding the causes. These causes are revealed only through the rational soul, thus leading us to knowledge.

Classification of Knowledge Types

  1. Sensation: Dependent on perception, leading to sensory memory. Common to animals and humans.
  2. Imagination: Gives rise to long-term memory. Common to animals and humans.
  3. Experience: Rational coordination of memories (1 and 2). Only humans possess this, leading to **Induction** (moving from particular observations to general principles).
  4. Understanding (Rational Thought): Argumentative rational thought. This involves two aspects:
    • Passive Intellect: The reception and exposure of data.
    • Active Intellect: The concluding passage, reaching a conclusion, and forming the general or universal representation of a concept. This knowledge is unique to humans and involves **Deduction**.

Systems of Inference

From an epistemological point of view, knowledge can be acquired in two ways:

  1. System of Inductive Inference: Moving from the particular to the general. Reality is explained from the bottom up, according to Aristotle. This emphasis on experience contrasts with the idealism of Plato.
  2. System of Deductive Inference: Moving from the general to the particular. Aristotle is credited with “discovering” **syllogistic logic**—a demonstrative argument with at least two premises from which a conclusion can be drawn.

By combining validity and truth, and incorporating negative, universal, and particular premises, this structure was later utilized by the Scholastics to maintain their position of authority (though deduction generally does not contribute new information).