I speak of Socrates and Plato as if they were interchangeable, often, and I think that approach is justifiable. Still, it requires a bit of explanation.
I think that it just practically makes the most sense to treat Plato’s Socrates as if his words communicate both what the historical Socrates believed and also what Plato himself believed.
I’m not saying that Socrates and Plato never actually differed, or that Plato never found ways to put his own thoughts into Socrates’ speech. That would be just as foolish as claiming the opposite, since either conclusion would have to be based on negligible evidence.
What I claim is that we can’t ever know! We can’t know what is Plato’s and what is Socrates’. We generally can’t know for sure which of Plato’s dialogues are earlier and which later, just as we likewise couldn’t know if Plato lied about Socrates’ views later in life when he was old and inflexible in his views, or earlier in his life when he was young and overconfident in his insights.
So then, we might as well not worry about it, especially since it is entirely possible that Socrates did think all the things Plato says he did, and that Plato accepted the teachings of Socrates without contradiction.
We don’t lose anything by treating Plato and Socrates as being in substantial agreement about the things Plato has Socrates say. To me it just seems like a sensible thing to do, rather than building hypothetical distinctions between the two on the foundations of ignorance and inadequate evidence.
Now, I also don’t mean to imply that Plato’s Socrates is the real one and the representations from others like Xenophon and Aristophanes must all be falsehoods. I believe we do best to treat them each as showing us Socrates from one angle, more or less accurately.
A surprising number of people seem to think that stories about one person shared from different perspectives must be in competition and they can’t all be true, but to me that seems very dubious indeed. If you got a handful of people together who knew me in different settings and different moments in my life, or even in the same context, and you asked each to describe me and tell stories about me, you’d probably get a different picture from every person you spoke to, even as there would be common features throughout. That’s what we find with Socrates, and I don’t know any reason why we should ever need to see it as being at all problematic.