Philosophy is sometimes accused of being void of content, nothing more than an indulgence at word-play and useless intellectual gymnastics. I don't think anyone is justified to hold such an opinion, especially after Karl Popper. After all, he set the standards of modern science by introducing the concept of falsifiability.
In the first part of his influential tome "The Open Society and its Enemies", Popper attacks a widely revered persona : Plato.
Plato lived at the very crucial time of the Peloponnesian War, the time when the ideas of individualism and democracy were introduced for the first time. It was a transition that Plato opposed, despite the influence Socrates had on him. Popper shows how the social model that Plato proposes is totalitarian, and how he manages to present it in a way that continues to appeal even to modern times. Plato's ideal society is one of rigid roles and no individuality. His theory of Forms (or Ideas) naturally supports such a model : perfection lies in the past because everything that exists is a degenerate copy of its ideal, primordial Form (this is a version of a concept that Popper calls "historicism"). Thus, any change away from the ancient, tribalistic societies is evil. An argument Plato uses is comparing society with the body of an organism. An organism cannot function if its parts seek roles that are different from their natural ones.
Plato manages to present his social model as just and good by clever philosophical tricks. One is to present the laws of tribalistic society as natural ones. In the same way that you cannot challenge gravity, Plato assumes that this applies for the laws of his ideal society. As these laws are part of the past, they are more perfect copies of their original Form. Another trick is to present concepts like individualism as inherently selfish and destructive for society. For Plato, being a free individual is not an option, it is not natural - it is egoistic and thus, evil. The reason why such clearly totalitarian ideas remain popular is because they prey on our natural urge to belong to a group.
Karl Popper has dug deep into the platonic texts and manages to elegantly explain and expose their origin and content. By doing so, Popper also offers us an important understanding of the democratic values that emerged when the tribalistic society collapsed. There is only one point that I think Popper gets wrong.
Popper briefly criticizes Plato's fame as "the nearest approach to Christianity before Christ" and it is here that I think he fails to make a case. Plato's fame is very much justified because Christianity opposes democracy with the same arguments and tricks that Plato uses. Popper argues that modern philosophers fail to see the connection between Plato and totalitarianism but he himself fails, in the same way, to see the connection with Christianity. It may be that Popper wanted to avoid insulting his religious readers. It's hard to believe he would have missed the similarities between Paul and Plato, as they both use the "body" comparison (1 Corinthians 12:12-26) for their proposed societal model. Inadvertently or not, Popper's criticism of Plato also reveals the totalitarian nature of Christianity.