Plato’s Theory of Forms and Aristotle’s Metaphysics

Posted on Oct 29, 2025 in Philosophy and ethics

Plato: The Intelligible World and Political Philosophy

The Intelligible World of Ideas

The intelligible world of ideas, according to Plato, is the true reality—the field where ideas are located. This reality cannot be accessed through the use of the senses but is reached by employing the most excellent part of the soul: reason. This authentic reality has a religious character and significant consequences in the fields of epistemology, ethics, and politics. Situated above all other ideas, we find the Idea of the Good.

Dialectic: The Philosophical Method

Dialectic is the philosophical method proposed by Plato to access the world of ideas. The notion of dialectic has several meanings:

1. Dialectic as a Rational Method

As a rational method, dialectic is identified with philosophy and science. Its characteristics include:

  • It is a cognitive activity, relying on the exercise of reason.
  • Its purpose is the knowledge of the intelligible world and the relationships between ideas.
  • Its ultimate aim is the knowledge of the Idea of the Good, which is the ultimate foundation of all reality.
  • It is a strictly rational activity, not based on perception, and does not accept hypotheses.
2. Dialectic as Erotic Impulse (Eros)

As an erotic impulse, it is a more emotional activity—intellectual and volitional—that assumes the feeling of love or the desire for beauty and joy in its possession. The object of this impulse is the aesthetic understanding of the intelligible world, and its ultimate aim is the aesthetic understanding of the Idea of Beauty.

The Philosopher-King

The Philosopher-King is the political figure indispensable for the realization of a just society. Plato’s dialogue, The Republic (or The State), presents the idea of the ideal state or society. In this ideal state, society is divided into groups according to how each group must satisfy basic needs (e.g., artisans create all necessary goods).

The figure of the Philosopher-King arises from two fundamental views in Plato’s political philosophy: his authoritarian conception and his basic intellectualist thesis. The theses that fundamentally support the claim for the Philosopher-King are:

  1. Objective knowledge of the Good is possible.
  2. Only those who possess this knowledge are qualified to lead society.
  3. The knowledge of the Good is included in philosophy.

Aristotle’s Metaphysics and Ethics

The Four Causes (Aitia)

For Aristotle, a cause (aitia) is the main factor upon which a thing depends. This is a broader notion than the current understanding of cause, which often only refers to the efficient and final causes.

A cause is any principle of being—that upon which the existence of a thing somehow depends, or any factor to which we must refer to explain any process. To understand a thing fully, we must look at the four ways of causation:

  1. Material Cause: That out of which something is made.
  2. Formal Cause: That which is the object’s essence or structure.
  3. Efficient Cause: That by which something has occurred (the primary source of change or rest).
  4. Final Cause: That for the sake of which something exists, or toward which it tends or may become (the purpose).

Happiness (Eudaimonia)

Happiness is the supreme good of humanity. Happiness (Eudaimonia) is that which accompanies the realization of the proper end of every living being. Rightful happiness is achieved by man when he performs the activity most suitable to him, and when it is done in a perfect way.

Since the soul is more proper to man than the body, human happiness will have more to do with the activity of the soul than with the body. Furthermore, happiness corresponds most closely to the part of the soul that is typically human: the intellect or rational soul.

Nature (Physis)

Nature is the intrinsic principle of motion and rest in natural beings. This notion was important to all Greeks, but Aristotle studied it in greater detail, particularly in relation to the issue of Forms (Ideas).

There are two basic, though interconnected, aspects of Nature:

  1. Nature understood as the totality of all natural beings.
  2. Nature understood as the very being (essence) of things.