The introduction of concepts under the guise of merely asking questions
The dialogue Philebus is set up as a standard Socratic dialogue. In it, Socrates converses with Philebus and Protarchus about the nature of knowledge. As typical, Socrates is in the position of inquisitor, trying to extract the concept of knowledge from his conversation partner. As described in other writings, Socrates’ role here would be like that of a midwife, simply guiding the process along without forcing any of his own concepts into the conversation.
I think this dialogue is a good example of a more general problem I have with Plato’s dialogues, as Socrates most definitely introduces concepts, both explicitly and implicitly, while not permitting his interlocutors the same privilege.
For example, in the first section of the dialogue, Socrates forces Protarchus to accept that there are two types of knowledge, one which is concerned with the Forms and one which is not. This may not be an unreasonable starting point, but it is not one that Protarchus would have come to on his own, and it is not one that Socrates argues for in any way. In fact, Socrates explicitly says that he is not going to argue for this position, but simply states it as a fact.
This pattern continues throughout the dialogue, with Socrates introducing new concepts and then using them to draw conclusions, without ever really defending them. For example, later in the same conversation, Socrates introduces the concept of the One and the Many, and then proceeds to use this concept to argue that knowledge must be One. Again, this may be a reasonable conclusion, but it is not one that follows necessarily from the concept of the One and the Many.
These two point have been explicitly declarations of novel terms, but I think Socrates’ implicit introductions to be even more egregious. Towards the latter half of the dialogue, Socrates starts to focus on “discovering” the hierarchy of pleasure and knowledge. Socrates states that since in most human pursuits there is something such as a superior and inferior, such as in music, sports, or religion, the same must hold true for knowledge and pleasure. In other words, it must be the case that either hedonistic-, or sophist-pleasures are to be pursued. The reason I find this introduction so problematic is because of how fundamental it is. It seems to me that a theory which holds mental and bodily pleasures to be equals, could be both internal consistent and provide a good framework with which to asses the human condition.
In general, then, I find the Philebus to be an unsatisfying dialogue because of the way Socrates uses his position of power to force his interlocutor to accept his own concepts without ever really defending them. In the best case, this makes the dialogue seem less like a conversation and more someone preaching to their coir. In the worst cases, Plato writes in such a way that entire classes of theories are dammed to never be discussed altogether.