Plato’s Theory of Knowledge: Ideas, Dialectic, and Love
Plato’s Theory of Knowledge
In the theory of knowledge, Plato was greatly influenced by his mentor Socrates, especially in his earlier writings. For Plato, knowledge is based on the duality of two worlds: the sensible (imperfect, changeable, deceptive) and that of Ideas (perfect, imperishable, eternal, immutable). The Sensible World consists of things in flux, as Heraclitus suggested, and the Intelligible World (of Ideas) is permanent and unchangeable and possesses the characteristics of the Being of Parmenides. Since the sensible reality is subject to constant change, it does not give us full and universal knowledge of the object; therefore, it is not valid. Thus, no knowledge can be reduced to sensation. As a reason for this, Plato proposes that the concept of things past is in the ideas because only they are stable and capable of being defined as valid and universal.
Knowledge and the Sensible World
The knowledge of the Sensible World is grounded in opinions (doxa), so it is invalid and cannot support science due to its changing character. According to Plato, all reality was acquired in another life and is already stored in the soul, so we do not actually know anything new, but we recall: this is reminiscence. For example, if Plato sees a white animal, a mosquito, with a long beak (a stork) that he had never seen before, he does not think it is a new reality, but he already knows what it is and only has to remember it. To remember, one resorts to science (episteme). The concepts that are recalled are absolutes (the Beautiful, the Good, etc.) and are the “templates” of real objects. For example, when we see a blond, tall, and strong man and another dark, short, and ugly man, we know that both are men because we have grasped the concept of Man and identified anyone who meets certain characteristics as a man. The theory of recollection appears in his work Meno. This is the main procedure, but three other methods are based on Plato’s reminiscence.
Dialectic
The first to analyze after reminiscence is the dialectic. The dialectic is the presentation and rebuttal of several partners to extract the essences of things and, thus, facilitate the ascension to the World of Ideas. This is the method followed by his teacher Socrates. Therefore, it is a method to remove the speaker of truth within him and give evidence of what is taught, and yet, research. On this basis, we can say that Plato’s dialectic is conceived from two positions. The first is that he considered it as the rational method to attain knowledge of Ideas. This being so, it is a method that removes the particular Sensible World to reach the general, the concept itself, ultimately to the idea. Therefore, the dialectic is a rational scientific method since its procedure is based on induction (set assumptions and verify them until they are confirmed). The second perception of the Platonic dialectic is as supreme science, which seeks to understand the ideas. Therefore, as it is the only science whose ultimate goal is to learn, all other sciences are subject to it. In short, the dialectic serves to unravel the ideas and way up from one another to reach the Supreme Idea: The Idea of Good. Thus, the dialectic is used by Plato as a process from things to the One, which is the Good.
Platonic Love
Another method for attaining true knowledge is Platonic love. This is a dialectic whose love is knowledge of the Beautiful in the World of Ideas. It is love that drives men to go on discovering, transcending the barriers of love for objects to the morality of love for souls, love for moral laws, laws to love science, and this, the desire to understand what is really beautiful, beauty itself.
Philosophy as Purification
Following these methods, even after writing his theory of knowledge, Plato describes philosophy as a means of purification, for which the philosopher has to prepare all his life because, at the time when a man dies, he is able to see Ideas directly. Therefore, the philosopher does not fear death because it is the way to Supreme knowledge.
The Myth of the Cave
All these methods are collected in one of his major works, The Republic, specifically in the Myth of the Cave:
“(…)- Well, I said, this image must be applied all over, oh, friend Glaucon!, To what has been said before, we must compare the region revealed through sight to housing prison-fire and light in it with the power of the sun. On the ascent to the upper world and contemplating the things of it, if you compare with the soul’s ascent to the intelligible region did not err with regarding my glimmer, that’s what you want to meet and that only the Divinity knows if by chance he is right. Anyway, here’s what I think: the last thing intelligible world is perceived, and with work, is the idea of good, but, once perceived, we must infer that she is the cause of all straight and that is beautiful in all things, that while in the visible world has created a light and its supreme intelligible in her sovereign and producer of truth and knowledge, and that is bound to whoever would proceed wisely in private or public life. (…)
“Instead, I said, any reasonable person should remember that there are two ways and two causes by which they dazzle the eyes: to move from light to darkness and to move from darkness to light. And, once thought the same thing also happens to the soul, not laugh insanely when I see some who, being dazed, not able to discern the objects, but to ascertain whether it is coming from a more luminous, are blinded by lack of usual or going from a greater ignorance to greater light has been blinded by too much fat and so happy to be considered the first soul, that so behaves and lives, and pity the other, or if you want to laugh at her, that her laugh would be less ridiculous if he were making fun of the soul that descends from the light.”
Here the connotations are evident that Plato intended to give ideas related to anthropology and epistemology. His rationalist idealism made later writers, notably René Descartes, base their theories on it.