 So we're trying to find out the difference between an idea and a notion, according to both Highless and Philanus. I know what you're thinking. It's like, why is this such a big deal? Trust me, right? This sets up Philanus's big point. Alright, so I'll really find this, right, in this exchange between Highless and Philanus, where Highless is kind of laying it out, right? So he says, I acknowledge Philanus that upon a fair observation of what passes in my mind, I can discover nothing else but that I am a thinking being. By the way, that's an allusion to Descartes. I am a thinking being, effective with a variety of sensations. Neither is it possible to conclude how a sensation should exist in an unperceiving substance. In other words, the color blue isn't just floating around out there, right? It has to be in a mind. But then, on the other hand, when I look on sensible things in a different view, considering them as so many modes and qualities, I find it necessary to suppose a material substratum, without which they cannot be conceived to exist. Philanus says, material substratum call you it? Right now he knows he's got Highless. He knows he's got it. Pray, by which of your senses can you acquainted with that being? These guys are empiricists. Both Highless and Philanus are empiricists. And if you can't trace that knowledge back to experience, they don't exist. Not only do you not know it, that thing doesn't exist. So Highless responds, it itself is not sensible, to which Philanus goes, Really? It's modes and qualities only being perceived by the senses. It's modes and qualities, not a thing. I presume that it was by reflection and reason you obtained the idea of it, Philanus replies. Highless says, I do not pretend to have any proper positive idea of it, to which Philanus is like, However, I conclude it exists, because qualities cannot be conceived to exist without support. To which Philanus says, It seems then you have only a relative notion of it, or that you can see it not otherwise than by conceiving the relation it bears to sensible qualities to which Highless says, Right. This is the problem. So notice there's a difference between ideas and notions. Remember, Well, think about this for a second. We look at this paragraph. Look at this paragraph. So first of all, Highless is saying, I don't have an idea of it. And it's like, wait, wait, you don't have an idea of it. That sounds suspicious. Philanus says, oh, so you only have a notion. So there's already this contract between an idea and notion, and ideas already seem better. Look at this language again from this passage. Look at this language again from this passage. I acknowledge Philanus that upon a fair observation of what passes in my mind, I can discover nothing. Look at that paragraph. Does any of this seem familiar? Does any of this seem familiar? Look at some of those terms. We've heard some of these terms before, haven't we? We've got reflection, sensation, material substance, substratum, qualities. Which philosopher has given even ideas? Which philosopher has given us these notions before, these terms before? Highless is Locke. Highless is Locke, right? Barclay is probably trying to be too polite, then just like really call him out. A Highless is Locke. Highless's theory is Locke's theory. Highless's theory is Locke's theory. Remember what Locke talked about this? We have sensation and reflection. There's sensation and reflection and there's qualities. Qualities and ideas. Ideas are in your head, they're experiences, qualities are in the object. There's a difference between the two. And material substance is what qualities adhere in. Okay. But you don't see qualities. You only see what they cause. You don't see material substance at all. And remember what Locke said, we have no general idea of material substance. I mean, that should have been, you know, way back. That should have been like, whoa, what are you talking about? We have no general idea of material substance. I thought you said that you can account for existence. You know, through this theory of knowledge, you can tell us what exists. Barclay is taking Locke to task with this dialogue. Barclay is saying, look, you promised to give me an account of knowledge that used only experience. You didn't require any innate ideas. Guess what the innate idea is in this dialogue? It's material substance, because you don't experience innate ideas. By Locke's own theory, you don't experience material substance. It's an innate idea. By Locke's own theory, material substance is not experienced. That makes it an innate idea. So this is really the point that Barclay is trying to make here. Barclay is basically accusing Locke of being a rashing list. That this notion of material substance must be supposed in order to claim that there is material substance. But that's not something you experience. Now, maybe Barclay could have gone a different way. Maybe he could have said something like, well, of course there are material objects. So I guess I have to give up being an empiricist and take on the rationalist idea of material substance. But Barclay is not doing that. Barclay says, Barclay says that that he's holding onto empiricism with an iron fist grip here. He's not letting go of empiricism. But you do not see or experience material substance. You only see and experience what material substance causes. Now, we keep calling it material substance, but who knows what it is? Because you don't see it. You don't see it. So, here's kind of a linchpin in Barclay's argument, Philanus' argument here. Here's the absurdity of a material substance. You have to be a rationalist. And with rationalism, it's not a matter of whether you're on a crazy train. It's a matter of which one. Or we can look at skepticism. What exists out there are material objects, but I can't see them or experience them. So, gee, I guess I don't know about them. So, like I said, Barclay is holding onto empiricism. He's going to hold onto empiricism more than he holds onto the idea of material substance. And that's why he reaches the conclusion he does. There are objects that exist that are just not material. And the reason why he's giving up on material substance is because he can't experience them.