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Idealism in Ancient Greece: Socrates, Plato, and Aristotle

Idealism in Ancient Greece

Idealism started in Greece almost concurrently with materialism. Its doctrine is founded on theorizing based on ideas. For idealists, ideas are more important than matter; they try to give teleological explanations of reality, that is, the final causes.

Three of the greatest thinkers of idealism—Socrates, Plato, and Aristotle—developed their thoughts on the mainland of Greece; its study centers were in Athens, known for being one of the most educated Greek Polis.

Before and during Socrates’ lives, philosophers called the Sophists emerged, defending the relativity of the truth, reducing it to rhetoric. According to them, truth was dependent on argument. That is to say, rhetoric was sufficient to not only convince others, but point the way to truth.

One of the most prominent Sophists was Protagoras, whom it is necessary to mention, since he proposed that "man is the measure of all things, of the things that are, as they are, and of the things that are not, as long as they are not".



Socrates applied a method called the Socratic method, by which, through questioning, the teacher could make the student come to new knowledge through his own logical deductions. Socrates tried to find the essence of things. To understand reality, its essence had to be known.

Another deep concern of Socrates was morality; he differed from the Sophists, who said truth was subjective and could only be demonstrated according to the ability of the interlocutor to convince others. Socrates believed in the duality of the soul and body and that, in order to transcend, one had to control the impulses of the latter and thus come to knowledge, which was clouded by the senses. By finding the essence of things, the soul could then handle itself correctly. In the Phaedo, a dialogue written by Plato, Socrates declares:

Consider, therefore, my dear, Cebes, if it is not necessarily inferred from all that we have just said that our soul is very similar to the divine, immortal, intelligible, simple, indissoluble, always equal and self-like and that our body perfectly resembles what is human, mortal, sensitive, composed, soluble, always changing and never resembling itself.



Plato was a disciple of Socrates, of whom he writes: "From him we can say that he has been the best of all that we have known in our time, the wisest and the most just". Plato's most important ideas regarding idealism are the realm of forms, reminiscence theory of knowledge and his ideas about the nature of the soul.

The Realm of Forms

Regarding the realm of forms, Plato proposed that all we can perceive of our reality are just imperfect shadows of ideas that are in another world, abstract, intelligible, eternal, and immutable. This is explained in detail in his work The Allegory of the Cave.

The Reminiscence Theory of Knowledge

The reminiscence theory of knowledge suggested that all knowledge had already been acquired by the soul before possessing the body. However, as they entered the body, sensory experiences deformed the knowledge that the soul already had. For this reason, Plato believed that to "recover" knowledge, the introspective should be used.

Plato makes a difference in remembering and evoking; remember is to remember something lived, evocation suggests a search in experiences, this is much deeper and meaningful.

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It is important to emphasize that many ideas of Plato were modified by the scholastic to be assimilated by the church.



Aristotle was Plato's disciple. Like Plato and Socrates, Aristotle believed in essence, but unlike Plato, who rejected the sensitive world and argued that only by disconnecting from the sensory deformations caused by the body could knowledge be obtained; Aristotle believed that the essence of things could be found if studied in nature. Unlike Plato, who believed that knowledge and nature were separated, Aristotle believed that knowledge was in the study of nature and were therefore intertwined.

Some of his most important ideas for idealism were: Causality, the prime mover, common sense, passive intellect, the hierarchies of soul.

Causes of Being

Aristotle considers this causes as that which composes the elements of existence.



The internal constituent of what something is made of, such as bronze in respect of the statue or silver in respect of the cup.


The form or model, that is, the definition of the essence.


It is the first principle where change or rest comes from

End or Purpose

It is the final goal, Aristotle says, for example, “Walking regarding health. Well, why are we walking? To which we respond: to be healthy, and in saying this we believe we have indicated the cause”.

Prime Mover

Aristotle formulates the principle of causality ("Everything has a cause") and reminds us that infinite regress is not possible

A is moved by B, B is moved by C, C is moved by D, and so on. Then, there would never be a prime mover and therefore there would never have been any movement. And the fact that there is movement is evidence that cannot be questioned. Therefore, there must be a first mover, source of the movement.

However, to be truly first, this mover must be immobile (i.e. unchanged permanence), because if it were moved it would in turn need a previous mover, and the regression would begin again.

To Conclude

Socrates, Plato, and Aristotle were very influential figures in philosophy, even now. A lot of their ideas are questioned and criticized, and some of them are demonstrably wrong, but we must put them into context, while wrong, they were pioneers in critical thinking.


Aristóteles. (1995). Física II. Madrid: Gredos.

Aristotle. (2006). Prior Analytics. Retrieved from The internet Classics Archive:

Hergenhahn, B. R., Henley, T. B. (2013). An Introduction to the History of Psychology. Belmont, Wadstworth.

Navarro Cordón, J. M. (2009). Historia de la Filosofía. Madrid: Anaya. Retrieved from

Platón. (2008). Fedón o del Alma. Madrid: Gredos.


Erin Day from Washington, UT on May 15, 2020:

Very interesting

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