Plato’s Enduring Influence on Western Philosophy
Influences on Plato
Despite the undoubted originality of Plato (427-347 BC), it is easy to find traces of ideas and problems already addressed by the pre-Socratics in his work. The influence of Parmenides and his school is clear in many of his writings and theses (he even dedicated the dialogue Parmenides to this philosopher). For example, we can see this in:
- The conception of Being as immutable
- The division of reality into two regions: the apparent world and the real world
- The parallel division of knowledge into two types: science or true knowledge, corresponding to the exercise of reason (known by Parmenides as the “Way of Truth”), and opinion, as a set of much lower-ranking truths offered to the senses (called by Parmenides the “Way of Opinion”)
But Heraclitus is also present (the dialogue Cratylus is a tribute, named after a disciple of Heraclitus). The “Heraclitean river”, or reality subject to permanent change, appears in Platonic philosophy in the concept of the “world of sense” or the group of entities that are offered to the senses. Anaxagoras contributes the ordering intelligence (nous), a forerunner of the Demiurge, the demigod who built the Sensible World, imitating the Intelligible World and giving it purpose, contrary to what was defended by the atomists, for whom expression was simply the nature of chance and necessity.
During one of his trips to Southern Italy, Plato encountered the Pythagorean ideas, which he held in high esteem. In Meno, he proves the theory of reminiscence through the demonstration of a mathematical theorem by a slave. The slogan of the Academy, “Let no one enter here who does not know geometry,” shows his recognition of the extraordinary value of mathematics (in the Republic, it is presented as a prerequisite for dialectics). Other examples of Pythagorean influence include:
- The claim of reason as a tool for knowledge
- The primacy of the soul over the body
- The theory of reincarnation of the soul
- The fact that the Demiurge created the world of sense from mathematical models
The Orphic religion is also present in his thought, especially in its radical anthropological dualism, with the overvaluation of the soul and contempt of the body (seen as a simple imprisonment of the soul), and theses on the divine and immortal nature of the human soul and its moral ideal of asceticism or purification.
But surely, the author who most influenced Plato’s thought was Socrates, whom he met in his youth and who initiated him into philosophy. The Death of Socrates (399 BC) affected him deeply, so that the figure and thought of his teacher run through many of his writings, especially in the so-called “Dialogues of Youth” (Apology, Crito, etc.). His imprint can be traced throughout Platonic philosophy, including:
- Consideration of dialogue as the proper way to philosophical inquiry and truth
- Primacy of the soul over the body
- Need to address the care of the soul
- Moral and political intellectualism
- Belief in the importance of providing universal and necessary definitions of concepts, a belief that favors the thesis of the existence of essences or universal entities
- The theory of reminiscence, a necessary complement to Socratic maieutics
However, we cannot bypass the Sophist movement, which, in contrast, also influenced him. The whole philosophy of Plato is a consequence of his quest to dramatically exceed the Sophists. For example, on the following issues:
- Facing the teaching practice of giving speeches, Plato proposes dialogue as the field of philosophical inquiry and discovery of truth, requiring active student participation.
- Against Sophist relativism and skepticism, Plato defends the existence of absolute realities (Ideas) that are the foundation of the possibility of objective knowledge.
- He critiques the moral relativism of the Sophists.
- Finally, against the Sophist conception of language and of reason as mere instruments for the defense of any personal interest and success in the polis, Plato offers a conception of language use and reason as a setting to achieve an objective and truths common to all human beings.
Impact of Plato
Platonic thought is present in one way or another in all of Western thought (Whitehead said the whole history of philosophy is nothing but a bunch of notes in the footnotes of Plato’s works). Here are some of the most obvious and unanimously accepted influences.
In Ancient Philosophy
In 387 BC, Plato founded the Academy in Athens, one of the major schools and research centers of Antiquity (until 529 AD, when it was closed by the Christian Emperor Justinian). In this school, music, astronomy, and mathematics were taught, and, as a culmination of studies, philosophy. Important mathematicians and astronomers were highlighted, but natural history (biology) and the study of the Laws were not neglected. Of the various periods the Academy went through, the most faithful to Plato’s thinking is the first, the Old Academy (4th and 3rd centuries BC), which follows Plato’s teachings while accentuating and mathematizing Pythagorean ideas found in his later writings. Neoplatonism (3rd-6th centuries AD) extended the thought of the Academy and offered a mystical interpretation of his thought. Plotinus (205-270), Porphyry (232-304), Iamblichus (240-325), and Proclus (410-485) are its most important representatives.
Aristotle, Plato’s most important disciple, was trained at the Academy. Although he criticized the theory of Ideas, rejecting the existence of transcendent things independent of the physical world, he maintained, along with his teacher, that along with individual realities there are universal entities (essences or forms), but not separate from the things of the world but in the individual. He also maintained that it is these universal entities that should concern science. The thesis of the divine and immortal nature of reason (in its most excellent form, what Aristotle called “intellect”) is also Platonic. Moreover, considering man as a social being by nature or the importance of knowledge for moral and political life (in more moderate terms than Plato) also show a clear imprint of his teacher.
Medieval and Renaissance Influence
Plato understood the idea of property (as Truth, Beauty, and Goodness, high and pure, creator and director of the world) in terms that were easy to fit into the monotheism of the Jews, Christians, and Muslims. His conception of the soul and important ethical theses also have an affinity with these religions. Therefore, it is not surprising that this philosopher is present in Islamic thought (Al-Farabi (870-950)), Jewish thought (Avencebrol (1020-1059)), and Christian thought. In medieval Christian thought, he is found in St. Anselm (1033-1109) and St. Bonaventure (1221-1274), but undoubtedly, his influence is most prominent in St. Augustine (354-430). Augustinian anthropological dualism is reminiscent of Plato. Augustine also believed in the existence of universal entities (for this author, located in the mind of God) and rejected an empiricist conception of knowledge, replacing reminiscence with divine illumination. For his part, Aquinas uses the Platonic notion of participation to account for the relationship between God and creatures, and his ways of demonstrating the existence of God (especially the fourth, by the degrees of perfection) are influenced by our philosopher.
The Renaissance marked the renewal of Greek thought, prominently that of Plato, first through the Platonic Academy of Florence, especially Marsilio Ficino (1473-1546), then with the utopias of Thomas More and Campanella, inspired by Plato’s most important work, Republic. In the modern age, although forgotten by empiricism, he has some presence in rationalism. For example, Descartes defended a nativist theory of knowledge that keeps a clear resemblance to the theory of reminiscence, and he shares Plato’s enthusiasm for the exercise of reason and suspicion of the ability of the senses, as well as anthropological dualism. It is not wrong to point out that Kant was inspired by Plato’s Ideas for his “pure ideas of reason”.
Contemporary Philosophy
Contemporary philosophy tends toward empiricism and anti-metaphysical thinking (just remember Marx, Nietzsche, and neo-positivism), but the Platonic footprint is also highlighted in some important trends, such as the phenomenology of Husserl and Scheler, who, like Plato, believe in the existence of eternal, immutable, and universal entities (essences) and the need and possibility of strict knowledge, knowledge involving absolute, ideal objects. Finally, we cannot forget the famous philosopher Karl Popper (1902-1997), who has an ambivalent attitude toward Plato. In The Open Society and Its Enemies, he wanted to show that Plato was the spiritual father of the totalitarian conception of the State and an enemy of freedom, but in other writings, he seems to hold theses very close to the Platonic. Popper considers that there are three “Worlds”: World 1, or the set of physical facts; World 2, or the set of mental states; and World 3, where objective truths and laws of science are located, independent of the other two. This World 3 is certainly very similar to the world of Ideas proposed by Plato.