Okay, so I’m minding my own business, working my way diligently through Plato’s Republic, when we come to the end of Book V and what knowledge, ignorance and opinion are. Quite simply, knowledge is knowing those things that are completely (e. g., the ideas); ignorance is not knowing those things that are not; and opinion is opining that which neither completely is nor is not in any way. Isn’t it obvious?
Sure, I’ll grant you that the double negatives can spin you ’round the first time you encounter them, but a slow consideration of the statements yields, voila, the understanding one would need. Still, I had some fun with them. One gentlemen wanted to assert that the only thing that we could know is that “Today is today.” I asserted, on the contrary, one could know that today is Tuesday. What about culture? Aren’t the names just human convention? And so forth. No. We can know that today is Tuesday. We cannot know, for example, that today is Friday. The gentleman conceded. “Okay. But that’s all we can really know.” Hmmmm. No, we can know that what is true cannot at the same time also be false. We can know that the One cannot be many. And so forth. He was skeptical and left claiming that when he came back, he would prove me (and Socrates) wrong.
Then there was the other gentleman who caught me after class with the proposition: “Wouldn’t you say that all knowledge is really just opinion that coincides with God’s omniscience?” (Shades of Berkeley!) No, I replied, we can really know things. “But can’t we be wrong?” Certainly. “So then all we know is merely opinion.” But that itself is a claim to know something and is not itself an opinion; therefore not everything we know is opinion. He frowned. This was not going the way he had planned. He left mumbling something about how I turned his words around on him. (Funny, that’s the same thing Euthyphro, in the eponymous dialogue, says of Socrates. Or for that matter, what the power-pragmatist Thrasymachus says of Socrates in the very Republic under consideration today.
And I put away my notes and headed to my office to blog about the day’s events.