Let’s take a look at some of the best and worst ideas found in Plato’s philosophy. Plato’s best ideasThe theory of formsPlato established a significant difference between what we can perceive through the senses and what we can perceive through reason. Plato believed that the search for justice should be the main purpose of any ruler. Plato’s worst ideasPlato’s views on womenPlato has extremely mixed and inconsistent views on how women should function within governing systems. “Featherless bipeds”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.