Plato was one of the most influential thinkers in the history of philosophy. Plato’s concepts laid the groundwork for Ancient Greek and western philosophy and are still considered immensely influential to this day.
His contributions are easily recognizable across education, politics, ethics, epistemology, and psychology. The twentieth century thinker, Alfred North Whitehead, once described European philosophy as “a series of footnotes to Plato.” While many of Plato’s concepts are undeniably crucial for the progression of western philosophy, some of his ideas have not aged well.
Let’s take a look at some of the best and worst ideas found in Plato’s philosophy.
Plato’s best ideas
The theory of forms
Plato established a significant difference between what we can perceive through the senses and what we can perceive through reason. He described the latter as “forms.”
For Plato, “forms” combined with language create the basis of scientific knowledge.
Plato believed that the phenomena we perceive with the senses are the constant changes of the ideal “forms” that can only be perceived with reason. In Plato’s world there is a universal, singular “ideal” of a structure like a house, and the houses that we see in our daily experience are only tangible manifestations of that ideal—manifestations subject to change.
Plato urged philosophers to try to understand the ideal world. What we can perceive with our senses never remains while in the world of ideas and “forms,” everything is immutable and eternal much like the soul.
Governments centered on justice
Plato’s model of the Republic is based on justice. Plato believed that the search for justice should be the main purpose of any ruler. He also believed that governing was a kind of art like painting or literature and that the art of governing well requires good reasoning or a discerning interpretation of “forms.”
This is why Plato invented the moniker of the “philosopher king.” He believed that a ruler should have the intellectual prowess of a thinker in order to govern correctly.
Plato traveled twice to Syracuse, Sicily in attempt to put his philosophical project into practice and demonstrate that it was a viable form of governance. He was met with opposition, however, and secretly fled back to Greece.
Plato’s worst ideas
Plato’s views on women
Plato has extremely mixed and inconsistent views on how women should function within governing systems. Although he believed that women were just and could assist in governmental processes, he also compared them to children.
Plato also derided women’s biology as affecting their aptitude to think logically, saying that their bodies were similar to a “rebellious animal without reason,” driven by its appetite. He defined the female reproductive system as an “animal eager to procreate.”
For Plato, the female body had a life of its own: “if the uterus remains for a long time without producing fruit; it becomes irritated and wanders throughout the body, closes the air passage, prevents breathing, puts the body in danger and engenders a thousand diseases.”
Such misguided ideas about the female body were widespread amongst thinkers of the time. Even Hippocrates, the father of modern medicine, wrote in his Treatise on Women’s Diseases about something he called “hysterical suffocation,” a respiratory disease that appeared when the uterus migrated to the upper abdomen in search of fluid.
One of Plato’s ideas that completely missed the mark was his attempt to categorize humans with birds, dubbing them “featherless bipeds.”
According to legend, Diogenes of Sinope, the famous “cynic” of Ancient Greece, became angry with Plato’s classification that compared men to birds. Diogenes decided to pluck a rooster and take it to one of Plato’s classes where he proclaimed “here is Plato’s man.”
Plato’s logic for associating humans with birds was the ability of both to master coordinated movement.
Platonic Academy of Athens
The Platonic Academy of Athens was founded by Plato around 387 BC. The academy, which was destroyed during a war, was subsequently rebuilt in 410 AD. The Academy was eventually permanently shut down by the Emperor Justinian in 529 AD. The school was dedicated to the study of knowledge, mathematics, medicine, rhetoric, and astronomy.
The Platonic Academy had three notable periods. The first of these periods was the ancient academy, comprised of the disciples closest to Plato until 260 BC. They closely followed the school of thought invented by their teacher, namely that knowledge is based on justified, true beliefs.
The Middle Academy was the second of these periods and was founded in 244 BC. It was characterized by the return to the thought of Socrates, constituting a new distance from the original thought of Plato. Irony, skepticism, doubt, and interrogation dominated.
The New Academy was the last of the three periods and began around 160 BC. Represented by Carnéades and Philo of Larisa, this iteration of the academy taught that one cannot have definitive knowledge of an outcome since it is impossible to have total certainty or uncertainty.
Plato’s most famous student was Aristotle.
Related story: The Platonic Academy of Athens: The World’s First University