De Anima (On the Soul)
140. Summa I q.84 a.7: Why We Think Through Images, and Why the Brain Isn't the Organ of Thought
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[0:00] To the seventh one proceeds thus: It seems that the understanding is able to understand and act through the understandable forms which it has within itself, without turning itself to the phantasms. Okay. Now, what Aristotle teaches in the third book about the soul is that even after you have the understandable act in your mind, right? When you want to think about what a triangle is, right? You have to form an image of a triangle, right?

[0:33] So you consider the what it is of what you're imagining. The what it is is something universal, right? But the what it is is something you're imagining, okay? And so, if your imagination is injured,

[0:52] then that interferes with thinking, right? Okay. Now, some people, you know, they think because of that that the the brain, where the images are, that the brain is the organ of thought, right? Okay. I remember having in class, you know, you know, kind of a tough-minded modern or whatever call, and and he was convinced that the brain is the organ of thought, right? And I said, you know, blow on the eye interferes with seeing, right?

[1:29] And a blow on the brain interferes with thinking, right? So if a blow on the eye interferes with seeing, that's a sign that that the eye is the organ of sight, right? And a blow on the brain interferes with thinking. That's a sign that the brain is the organ of what? Thought, right? You see, yeah, that's his argument, right? Okay. Or alcohol, is it going to the brain interferes or affect your thinking, right?

[1:53] Okay. Lesions in the brain affect the thinking and so on. Okay. Therefore, the brain is the organ of thought, right? Okay. So he thought this argument was and I'm the final word on the subject. So I said, okay, let's consider your argument here. Suppose you and I are in a room with no windows, and the only source of light was a little light bulb there in the center of the room, and the light bulb is on and so on, so we can see each other, right?

[2:22] Now I take a book and I bang the light bulb, and all of a sudden, right? You're no longer able to see me. So a blow on the light bulb has interfered with what? You're seeing. Therefore, the light bulb is the organ of sight.

[2:42] Well, notice, huh? A blow on the light bulb interferes with what? Seeing in this example, a blow on the eye interferes with seeing, right? But one case interfering with the organ. Another case interfering with the object, huh? See, if you leave this room, it interferes by seeing you. Yeah. Not because you are in any way as the organ of my sight, but because you, or the color in you, right, is the object of my sight, right?

[3:15] Okay. So he said the fact that he blow on the brain, or alcohol going to the brain, or injury to the brain, interferes with thinking, falling asleep, right, and so on. Is a sign that there's a connection between the brain and thinking, right? But that doesn't tell you whether the connection is one of organ or one of object. Hmm.

[3:40] And when Aristotle discovers what the object of reason is, huh? Its own object, right? It's the what it is of something you sense or imagine. So

[3:55] what you imagine is on the side of the object of reason, huh? Okay. And his other arguments whereby he shows that reason is not a body, huh? And therefore the brain cannot be the organ of what thought. Therefore it must be related to thought in some ways the object. And when you understand that the object of reason is the what it is of something sensed or imagined, then you see the connection, right?

[4:20] And Aristotle would develop this proportion that the images are to to thinking something like the exterior object is to seeing or hearing. And what you're seeing is the color of something out there, right? Or you're hearing the sound of something out there, right? Or you're smelling the odor of something out there, right? So if what you're seeing is the color of something outside you, you can't see without that exterior thing being there, right?

[4:54] And if the object of reason is the what it is of something sensed or imagined, you can't think about the what it is of something imagined without imagining something. But that makes it be on this side of the what object, right? So Thomas is going to develop this here, and we'll see in this thing.

[5:14] First objection, which is saying you don't have to turn to the images, which is contrary to our experience, right? We don't want to experience when the images are not there, right? We can't think, right? The understanding comes to be an act through the understandable form by which it is informed. But for the understanding to be an act is for it to understand. Therefore, the understandable forms suffice for this that the understanding understand and act.

[5:49] Without this, that it turns to the what? phantasms, huh? Moreover. The imagination more depends upon the senses than the understanding upon the imagination, but the imagination is able to imagine an act with the sensible things being absent.

[6:13] Therefore, much more can the understanding understand an act, not turning itself to the what phantasms Moreover, of bodiless things there are not any images, because imagination does not transcend time and the what continuous. If therefore our understanding is not able to understand something in act, unless it turns to the phantasms it would follow that it could not understand something bodiless, which is clearly false. For we understand to some extent truth itself, and we understand God to some extent and the angels, right?

[7:03] Okay. But against this is what the philosopher says Aristotle, right? In the third book about the soul, that the soul understands nothing without an image.

[7:18] I answer that it is impossible for our understanding, in the state of the present life, in which it is joined to a undergoing body, to understand something in act except by turning itself to the what images.

[7:39] And this appears by two signs, huh? In indications, first because since the understanding is a certain power not using a body organ, in no way is it would it be impeded in its act through the injury of some body organ, if there was not required for its act the act of some power using a body organ. Because we simply experience, right, that the brain, right, and so on.

[8:14] The imagination is tired, or it can't imagine something, or you're asleep and you don't have control of your images, and so on, right? And you can't understand certain things. Ah, for they use the body organ. Sense and imagination use the body organ, and the other powers pertaining to the sense part of the soul. Whence it is manifest from experience, you'd say then, that in order for the understanding to understand and act, not only when it takes knowledge to begin with, right, but also in using the knowledge it has acquired, right?

[8:54] I've acquired some geometry, right, but if I want to think about what a triangle is, I imagine a triangle, right, and then I. But understand what a triangle is in that image, so to speak, right? Okay, and the object.

[9:19] Once is manifest that in order that the understanding understand and act, not only when it's taking knowledge newly, but also using knowledge already acquired, it requires the act of the imagination and of the other powers. For we see that the act of the imagination, or the power to imagine, being impeded through the injury to the organ, as in those who are beside themselves, right? The phrenetic. And similarly, when the act of the memory power is impeded, right?

[9:56] A man is impeded from understanding an act. Even those things of which he has already taken the knowledge. Secondly, because everyone can experience in himself that when he tries to understand something, he forms some images, right? For himself, but we have examples in which he inspects what he desires to understand.

[10:24] And hence it is that when we wish to make another understand something, we propose to him examples, right? From which he can form images suitable to what understand, right?

[10:43] Okay. Now, up to this point, he's been giving what our experience, right? I want to think about what a triangle is in and you've got to form an image of a triangle, right? And that's a matter of my experience, right? Yeah. And and the early experience that injuries done to the brain, right, interfere with what thinking about something, right? I remember when I got to the doing solid geometry, Euclid, right?

[11:09] You're trying to imagine some of these things, right? And then your imagination is maybe not good enough, like a mathematician's imagination. So I constructed, you know, some cardboard, some of these geometrical figures, you know, to help my imagination. We had one hanging down from the the light in the kitchen, you know, or over the table, you know, hanging down this geometrical figure, so I could pursue my higher studies, right?

[11:33] Yeah. But no, if you can't imagine the, you know, the thing, then you you can't what understand it, right? You know. That drove your wife crazy. Yeah. So that probably drove your wife crazy crazy.

[11:54] The reason of this is because the knowing power is proportional to the knowable, right? Whence the understanding of an angel who is wholly separated from the body, right, is proper his own object, right, is an understandable substance separated from the body, and through understandables of this sort, he knows what material things. But the understanding of the human understanding of man who is joined to a body, right, his own object is the quidditas, the what it is, right, or the nature, some nature existing in bodily matter.

[12:43] And through these natures of visible things, he ascends, right, also to some knowledge of what invisible things, huh, immaterial things. But it's of the. Definition, you might say, of such a nature that it exists in some individual, unlike Plato who had this world of forms, right? Which is not without some bodily matter, just as is of the nature of the stone that it be in this stone, and of the nature of the horse that it be in this horse, and thus about others.

[13:23] Whence the nature of stone or of any other material thing is not able to be known completely and truly, except to be known as existing in this particular. But the particular or individual we apprehend by sense and imagination, and therefore is necessary for this that the intellect understand and act its own object, that it turn itself to the images, that it may look upon the universal nature existing in the what particular, right?

[13:57] So when I think about what a cat is, I imagine a cat, right? And I'm thinking about the what it is, the what I'm imagining, okay? The same way when I think about the triangle or the square.

[14:11] If, however, the proper object, its own object of our understanding, was a separated form, or if the natures of sensible things subsisted not in particulars, according to what the Platonists thought, right? It would not be necessary that understanding always, in understanding, turn itself to the what phantasms. I say

[14:39] it helps you to understand that to see the the proportion that Aristotle gives in the third book, I mentioned already, right? Where he said that the

[14:51] images, that the images are to the understanding, something like exterior things are to the senses, right? The exterior colors, are to the senses. Okay. So although the color I've been talking about here in this bookmark, right? That color is in no way the organ of my sight, is it? And the seeing is not taking place in that bookmark, is it? The seeing is taking place up here, right?

[15:42] Okay. But can I see the color of this without this being here? If you took this bookmark out of the room, could I see the color of it? No. No. See. But nevertheless, this exterior thing here is in no way the what organ of my sight, right? It's all inside of the object of my sight, right? Yes. See, so because I am seeing the color of this bookmark, right?

[16:10] I can't see the color of this bookmark without this bookmark being there, right? Okay. Well, the same way, the proper object of the understanding is what it is, not of some immaterial thing, but what it is of something that is sensible, like a man or a dog or a tree, or something imaginable, like a square or a circle or something like that, right? So it can't what understand what it is of a triangle without there being a triangle there, so to speak, at least in imagination, without imagining, right?

[16:52] Or at least having an image. It can't understand what a dog is or what a cat is without imagining a dog or a cat, because this is the what it is of what he's imagining. Namely a dog or a cat. Okay, it's not a object existing by itself.

[17:13] You see the the proportion there. Okay. Okay. That's what misleads people, sometimes, into thinking that the brain is the organ of what thought, right? Because injury or blow or alcohol going to the brain interferes with what thinking, right? But interferes the thinking not by interfering with the organ of thought, because there isn't an organ of thought, but it's interfering on the side of the what object, right?

[18:02] Wow. Because it impedes the production of the phantasms, and therefore you can't. Yeah, yeah, yeah, yeah. Okay. That's why when we haven't met someone, we always imagine them wrong differently than they actually are. Yeah.

[18:23] Now, let's go back to first objection. The first objection says the understanding comes to be an act through the understandable form by which it has been informed. But the understanding, but for the understanding to be an act, it's for it to understand. Therefore, the understandable forms are enough for this that the understanding understand an act without its turning to the phantasms.

[18:56] The first, therefore, should be said that the species or forms conserved in the possible understanding exist in it habitually. When in act is not understand, as has been said above. Whence, in order that we might understand enact, it is not suffice the conservation of the species, right? But is necessary that we use them, according as they belong to the things of which they are the species, which are natures existing in what particular things, right?

[19:31] I mean, the what it is that the understanding is understanding is the what it is of something singular, right? And so, without having the singular represented in the imagination, I can't think of the what it is of that thing. Okay.

[19:51] See how people get a big stop there with the with with the brain and thinking the brain is the organ of thought See. Now go back to the example there—of the guy hitting the light bulb, right? Now it's to show that that a blow on the brain interferes with thinking is a sign that there's a connection between the brain and thinking, right? Okay. But what that doesn't tell you is whether the connection is one of organ or one of object, right?

[20:24] A blow on the eye interferes with my seeing you, right? Because in that case, it interferes the organ, right? But you leaving the room interferes with my seeing you, right? Not because you are the organ of my sight, but because you are in some sense the object of my sight. It's the color of you or something out there that I am going to see, right? Okay. Can can you say, for other people, use an example?

[20:54] You know, it's like a piano, piano and the piano player. I mean, it's like if we smash the piano, there won't be any more piano music. That doesn't prove that there wasn't a piano player. Necessarily. Yeah, but it's not exactly the same comparison there. Okay. If we blow you up, right? That's going to interfere with my seeing you, right? Yes. But not that you've blown up the organ of my sight, but because you interfere with the object of my sight, right?

[21:24] The object of my sight is the color of something out here—the color of your garment, right? Or the redness of this machine here, right? You see? Or the redness and whatever it is there of the bricks over there, right? Okay. The whiteness of the wall or something, or the redness of the of the thing. So if you take that fire extinguisher out of here, I'm not going to be able to see the redness of it, am I?

[21:47] Say. But that's because you're interfering with the object, right? Okay. So as I sometimes say, put it in logical terms. If the brain is the organ of thought, right? Then a blow on the brain interferes with thinking. But a blow on the brain does interfere thinking. Therefore, the brain is the organ of thought. Is that argument good? Can you say? Can you run on that for you?

[22:19] Yes, please. There's. Some clever trick there. If the brain is the organ of thought, then a blow on the brain, or alcohol going to it, and so on, and a blow on the brain will interfere with thinking. See.

[22:56] But a blow on the brain does interfere with thinking. Therefore, the brain is the organ of thought. But it's still just an argument, right? If the brain is the organ of thought, then a blow on the brain interferes thinking. But a blow on the brain does interfere thinking. Therefore, the brain is the organ of thought. That argument good? No,

[23:43] it's not. Okay. Now, some consequence or? Yeah, there's two kinds of defect an argument can have, right? Yeah. One is that the premises can be false, right? Or one of them be false. Or the other can be the conclusion doesn't follow from the premises, right? Okay.

[24:01] So, what's the defect in this argument? The premises false? No. It is true that a blow to the brain does interfere thinking. That's true. And it is true that if the brain is the organ of thought, right? Yeah. Then a blow on the brain interferes thinking, right? Yeah. Right. Okay. But does the conclusion follow from those two two premises? No. See. Well, you know, in logic, I always point that out, right?

[24:33] If Burcus dropped dead last night, then Burcus will be absent from class. But Burcus is absent from class. Therefore, he dropped dead last night. No. See. If the only way that Burcus would be absent from class is if he died, then you could argue it, right? But that isn't true, is it? Okay. So I say that's wishful thinking. I tell the students. But it's not logical thinking.

[25:01] I'm interested in your wishful thinking. Now, the other way you can say that if a if a blow on the brain interferes with thinking, then the brain is the organ of thought. Okay. But a blow on the brain does. Interfere with thinking. Therefore, the brain is the organ of thought. Okay. Now, in this second thing, does a conclusion follow from the premises? If a blow on the brain interferes with thinking,

[25:29] then the brain is the organ of thought. But a blow on the brain does interfere with thinking. Therefore, the brain is the organ of thought.

[26:30] First premise is not necessary. Yeah. Necessarily so. This conclusion follows from those premises if you lay those down, right? Okay. But the if-then statement is not true necessarily, right? See, if a blow on the brain interferes with thinking, then you can say the brain has some connection with thinking, right? Now, if the only connection could have with thinking is to be the organ of thought, then you could conclude this, right?

[27:00] You could say this is true. But as in my example of the light bulb, right? You know, if a blow on the light bulb interferes with seeing, then the light bulb must be the organ of sight, right? Well, obviously, it doesn't interfere with seeing on the side of the organ, does it? It interferes with seeing on the side of the object, right? Okay.

[27:26] So this, in the second argument here, the form is good, but the matter is bad. In the first argument, form is good, but the matter is bad because the if-then statement is not true. Okay. Could you say that whole thing again? Which the the form is good in which one? In the second one here. Here it's the reverse. The matter is good. Right. Because an if-then statement can be true even though the simple statements are not what.

[28:03] Okay. True, right? Now, if Socrates is a mother, then Socrates is a woman, right? That's true. Even though Socrates is not a mother, Okay. And so then, if you are a mother, then you are a woman, right? That's true. If I am the number two, then I am half of 4. That's true. See, if-then statement doesn't say that the simple statements it's composed of are in fact so, right?

[28:29] It's saying that if this one is so, then that will be so, right? So, if the brain is in fact the organ of thought, right? We're not saying in fact it is; we haven't proved it is, right? Yeah. Then, in fact, a blow on the brain will interfere with thinking, right? Okay. That's true, and a blow on the brain does interfere with thinking, but the conclusion it doesn't follow.

[28:51] The form is bad. Okay. What's the form you're in there? You're saying you're reasoning from what? The affirmation of the consequent, right, to the affirmation the antecedent. If I am a dog, then I'm an animal. True or false? True. Yeah. But I'm an animal. Therefore, I'm a dog.

[29:23] Doesn't follow, does it? If I'm the man who what murdered his wife, right, then I'm a man. True or false? If I'm the man who murdered his wife, then I'm a man. It doesn't follow. Sure. If I'm the man who murdered his wife, then I'm. Then I'm a man. That's true. Yeah. It's also true that I'm a man. Therefore, I'm the man who murdered his wife. right I tell the students, I put you all in jail today, right?

[30:02] If you're the man who robbed the bank today, then you are a man. True or false? True. But you are a man. True, right? Therefore, you are the man who robbed the bank, right? You see the idea? You see, you can't reason from the affirmation of the consequent to the affirmation of the antecedent. You can reason from the affirmation of the antecedent to the affirmation of the consequent.

[30:27] Okay. Experience. Sure. Okay. You see the idea? So if you reason this way, his matter is good. His premises are true, but the conclusion doesn't follow. If you reason this way, conclusion follows, but the premises are not? Both true. One of them is false.

[31:08] Now there are four people here. I'm going to buy you all twenty dollar book. Okay. Now four times twenty is what? Hundred. So it's going to cost me hundred dollars, right? What's wrong with that? There are four people here, right? Yeah. The book does cost twenty dollars. Mm-hmm. But I'm multiplying correctly. Right. Yeah. Okay. Now let's put it another way, right? Let me buy a book for all the students here, right?

[31:33] Twenty dollar book. And there's three students here. The book is twenty dollars. So three times twenty is sixty. It's four students. Yeah. There, I multiplied correctly. Three times twenty is sixty. But one of the numbers was incorrect, right? Yes. So there's two ways my checkbook or something like that can get off. Yeah. Either I didn't add or multiply or subtract correctly, right? Uh-huh. Or I didn't have the right number to add, subtract, or correct, right?

[32:05] Hmm. So essentially, you have both things wrong. Yeah. Aristotle refutes. Melissus there, right, in the first book of Natural Philosophy. He both has false premises and his conclusion doesn't follow either. So he has both defects. But all you need is one defect to say the argument is bad. Mm-hmm. Okay. But for an argument to be good, both the premises have to be true and the conclusion has to follow necessarily.

[32:36] That's where Aristotle talks about demonstration and logic. He does so in two books: the Prior and the Posterior Analytics. We call them in English. Yeah. But the Prior Analytics is looking at whether something follows necessarily or not, right? The Posterior Analytics is looking at whether the premises are necessarily true or not. And both are required, right? Yeah. Before you're sure of the what conclusion, right? You can have one of those without the other, right?

[33:09] But both of those are necessary before you can be sure about the what conclusion, huh? So demonstration is a syllogism whose premises are necessarily true, and therefore it's a syllogism whose conclusion is necessarily what true, right?

[33:37] Right. Dialectical syllogism is a syllogism whose premises are only probable opinions, and so they may or may the conclusion is only what probable, right? Okay. But in arguments like induction or enthymeme or example, um, there the conclusion doesn't follow necessarily, right?

[34:09] The last Honda I bought lasted me ten years. The next Honda will last me ten years, right? Doesn't follow necessarily, right? No. See, we use that kind of an argument all the time. Right. Sure. Now,

[34:37] but to be necessarily true, both the conclusion has to follow necessarily from the premises, and the premises have to be necessarily true, right? In this case here, in the first one, the conclusion doesn't follow necessarily from the premises. Conclusion doesn't follow. Yeah. Even though the premises are true,

[35:03] it's like when I say, "You know, I'm going to buy you four guys each a twenty dollars book. " Yeah. It's going to cost me a hundred dollars. See, well, I know make know correctly how many people are here. There's four of you here now, anyway. I might know correctly the price of the book, twenty dollars, right? If I multiply it correctly, right, that's one kind of mistake.

[35:23] Another mistake is not to what to multiply the wrong numbers. But to multiply the wrong numbers correctly, okay? Have to make both mistakes. Don't know. If I multiplied incorrectly and I had the wrong numbers, I can't have any trust in the final result, can I?

[35:49] That might happen to be correct. Okay, so Dr. Perkwis was in the, you know, the. In the logic game, what's the shorthand for these? The first one is an error of. What do you call that? The the form is bad. It's the form. Bad form, but the matter is good, right? The matter is good, so I guess I'm trying to resolve it into like if A then B is your.

[36:18] Yeah, yeah, yeah. Is what they do in logic? They will extract the form of the argument, right? Yeah. Okay. In this case, the the form of this argument. Yeah. If A is so. Yeah. Then B is so. Yeah. B is so. Right. So. And then you're trying to say that A is so, right? Then A. Okay. So. Well, it doesn't follow necessarily from the form here because it's possible that B might be a result of many things, right?

[36:51] For example, if if A is something less universal than B, right? If I'm a dog, I'm an animal. If I'm a cat, an animal, right? Yeah. See, what's this dog's name? Rosie. Rosie. Rosie. Okay. If Rosie is a cat, then Rosie is an animal. If Rosie is a horse, then Rosie now that's true, isn't it? Yes. Rosie is an animal. She sure is. yeah. If Rosie is a horse.

[37:18] She's a beast, actually. Yeah, Rosie is an animal. You see? Okay. Or if A is? One of many possible causes of an effect, right? Okay. If Burquist is visiting his grandchildren, then he will be absent from class, right? Yeah. If Burquist is sick, then he will be absent from class, maybe, right? If Burquist's car has broken down, then he will be absent from class, right? If you know, there's been a tremendous snowstorm up here, right?

[37:52] Then Burquist will not come, right? See. So, if you see that Burquist does not come, then you know that. Any one of those in particular, is sick? No. You might have forgot. You see what I mean? Okay. That's clear. Yeah. Forget things, yeah. Yeah. So I mean, there are many things from which my absence could follow. Yeah. If I dropped dead, then I would be absent, right?

[38:21] Yeah. On that particular day. So, therefore, if I'm absent, I must have dropped dead. So I taught. I taught students that wishful thinking. It's not logical thinking, right? So if A, those are two two large classes, right? If A is something what? Is is one of many possible causes of B, right? Yeah. Then you can't conclude A from the existence of B, can you? Take take an astronomical example here, right?

[38:52] The ancients thought that the what sun went around the earth, right? Yeah. And we think that the Earth turns on its axis, right? Now, if I say, if the Sun goes around the Earth, then there will be day and night. But there is day and night, isn't there?

[39:11] Therefore, the Sun goes around the Earth. Does that follow necessarily? Ah, no. No. If the only way there could be day and night is by the Sun going around the Earth, then you could argue that way, right? Right. But if it's possible, say that the Earth is turning on its axis, right? Right. Then there's more than one possible cause, right, of day and night, from which day and night would follow, right?

[39:39] Okay. If the Earth turns on its axis, then there will be day and night. If the Sun goes around the Earth, right, then there will be day and night. So the fact of day and night doesn't tell you which one of those is necessarily the case, does it? If I'm opposed to Wesley Clark on abortion, then I'll vote against Wesley Clark. right? But is that the only reason why I might be opposed to him.

[40:23] I'm not serious. There are other reasons too, right? Someone else might be voting against him for some other reason, right? Yeah. Okay. So I say either way you reason, one case you're you're reasoning from two premises, but your conclusion doesn't follow. Other case, your conclusion followed, but one of the premises isn't true. So neither case have you shown that the brain is in fact the organ of thought.

[40:59] Read my writing here, right? I'm getting it to to see. So in the second version, the form is good, but the matter is bad. huh? One of the premises is false.

[41:21] Okay, right. Yeah. The first one, the premises are true. Yeah. But the form is not good. The conclusion doesn't follow. Which was which was I think that that's pretty much what I was having a hard time seeing was I mean I knew the conclusion didn't follow, but I couldn't see it until you did the A and B. So I make comparison to your checkbook, you know, where if the number that you got is wrong, right?

[41:48] Yeah. It's because either you didn't add or subtract correctly, or because you had the wrong number, right? And sometimes you go back checking over your book, you discovered that you added or subtracted incorrectly. Sometimes you discovered, you know, you wrote it in, you know, so in a kind of same illegible way, and and or put the decimal point in the wrong place or what it was, you know, That could be thousands of dollars.

[42:11] And and but okay. Okay, or you can make both mistakes, obviously. I think I think I'm I think maybe we've got it now. Yeah. Trying to remember from how many forms are there where the conclusion necessarily follows? With the if then argument, yeah. Well, there's two. If A is so, then B is so. A is so, then it's obvious that B is so, right? You know, if you admit that if A is so, then B will be so, right?

[42:41] That necessarily follows. Yeah. Then you admit that in fact B is so. Obviously, you got to admit that B is so, right? Okay. Now, the one that is more difficult. Saw

[42:53] some moon here. So one form is obvious: if A is so, then B is so. A is so in fact, therefore B is so. Yeah. No, you're admitting up here when you say "is so" then "B is so," admitting that B follows necessarily from A, right? Not yet saying that A is in fact so or that B is in fact so. Just saying if A is so, then B will be necessarily so, right?

[43:36] Yeah. So if you admit that in fact A is so, then you must admit that B is so, right? That seems clear. Now the other form is valid: is if A is so, then B is so. B is not so, therefore A is not so. Now that's not so obvious, right? And so we show what is not obvious to what is obvious, right? Ah. We say if A were so, then B would have been so, right?

[44:15] But we're given that B is not so, right? Therefore, A is not so, right? What we're showing, in sense, is that these three statements: if A is so, then B is so, and the statement A is so, and the statement B is not so. Those three statements are incompatible, right? Because these two together, by the first case, contradict that, don't they? Hmm. So these three statements can't be true together, can they?

[44:53] Right. Okay. So if you're given this as being true, and you're given this as being true, right? Then the third one must be what?

[45:05] False, right? Because if they were true, then this would have been so rather than that, right? Yeah. So, ah, this is the second case, but we show it for the first case because it's not as obvious like the first one is. Okay.

[45:27] You see? Because if A had been so, then B would have been so, but B is not so, right? So A cannot be so, right? So those are the two forms. So if you want to show a statement by the if-then argument, you have to look before, right? You want to overthrow it, you look after it. This is what Socrates does in the Meno, right? He's arguing with probability, but he argues that if virtue can, if virtue is knowledge.

[45:58] Then virtue can be taught, and then he tries to show that virtue is knowledge. Therefore, virtue can be taught, right? And then he argues, if virtue can be taught, there will be teachers of it, given the importance of it, right? And then he argues there are no teachers of it, therefore it cannot be taught, right? So he uses these two forms. that are good. But now the other two forms.

[46:26] If A is so, then B is so, and A is not so, and if A is so, then B is so, and B is so. Then you can show that nothing follows necessarily from these two by a very simple example, right? If I am a dog, then I am an animal. But I'm not a dog, therefore I'm not an animal. I'm a cat. Cat, yeah.

[47:15] Okay, and if I am a dog, then I'm an animal, but I'm an animal, therefore I'm a dog. Okay. I know it's why you can disprove this by examples. You can't prove these by examples. You can disprove by examples because only needs one. One example shows that something is not always so. Yeah. And it's not always so; it isn't what necessarily so. Right. Using this form here, if it's necessarily so, then it's always so.

[47:46] Oh. It's not always so; therefore, it's not necessarily so. Yeah. Okay. So one example is enough to show that something is not always so. Sure. So if I say man is always white, how many black men do you need to disprove me? Just one, right? But how many white men would would prove that man is always white?

[48:11] The world went on forever. You know, so white men are always being produced, but still not prove that man is always white. And I can give you infinite examples of numbers that are odd, right? Sure. That prove that every number is odd. No. Three, five, seven, nine. How many numbers you need? Go on, can't you see? So you can't prove a form by examples. You can disprove by example.

[48:44] So in this this form here, it's pretty obvious. You understand what it means to say if A is so, then B is so. Yeah. You're saying B necessarily follows A, right? So if you fact say that A is in fact so, you must obviously say that B is so. But then we use that to. To to prove this, okay, and we use this form to disprove these.

[49:08] If it follows, see here, people are going to have to see that B is not so that if you all think, right? Okay, and here they'll think it follows that A is so, right? Okay, but that followed necessarily. Then, when these are true, that would always be true too. But it's not always true when these are true, is it? If I am a dog, then I am an animal.

[49:34] I am not a dog, therefore not animal. Not always true, is it? B is not so. See, it's true that if I am a dog, I am an animal. It's true. It's true. I'm not a dog. Does it follow? Therefore, I'm not an animal. It's false. Therefore, not. Same over here. If I am a dog, then I'm an animal. It's true. I am an animal. Therefore. I am. a dog

[50:01] Now we have to go to a particular example to see that clearly. Is that right? Well, yeah, but notice what the example does. See, by this form here. If if this is a syllogism, right? Something follows necessarily. If something follows necessarily then it's going to always be so when the premises are so. But one example is enough to show that something's not always so. Right. And therefore, it's not necessarily so.

[50:28] You don't have a syllogism. All right. So, if the brain is organ of thought, then the blow in the brain interferes thinking. The blow in the brain doesn't interfere thinking. No, this is not a syllogism. It doesn't follow. Here, in that one it follows, huh? If the brain is organ of thought, then the blow in the brain interferes thinking. Um, consider if a blow in the brain interferes thinking, then the brain is organ of thought.

[51:18] If blow in the brain interferes thinking, therefore the brain is organ of thought. It follows from those, but this is not true. If a blow on the brain interferes with thinking, then the brain is the organ of thought. Because there's another possibility, right? It could be interfering with it on the side of the object, right?

[51:42] If I don't love some something, it can be a defect in my heart, or it can be a defect in the thing, right? Sure. If I don't love cancer, right, the defect is on the in the object, right? If I don't love God, then the defect is in my heart, right? But so can you say if I don't love something, the defect is in my heart? No.

[52:08] No. It could be in my heart, or it could be in the object. So I think most people in the academic world, at least they speak this way, they think that the brain is the organ of thought, right? Yes. And why do they think that, right? Well, it's because there's a connection between the brain and thinking, right? Right. And we use our brain when we think.

[52:50] And we probably all say, "use your brain," you know, My wife works for the Mass Brain Injury Foundation, right? And the slogan is, you know, use your brain when you have one, right, or something like that. No. So that's her. And

[53:03] so we all think of the brain, you know, as being the kind of organ of thought, but it really isn't. It's it's inside of the object, right? So it's the organ of phantasms or the organ of images. Yeah, yeah. And because the object of our reason is the what it is of something imagined, right? That you don't think about the what it is of something imagined without imagining, right?

[53:33] Just like to use Aristotle's proportion, there, right? Just like I don't see the color of your clothes without your clothes being here, right? But your clothes are not the what organ of my sight, are they? Right. They're on the side of the object of my sight. So if you take away your garment, I can't see it. I can't see the color of that robe because what I'm seeing is not color in some abstract sense, right?

[54:06] But the color of that robe there in front of me. And we understand what a triangle is, but a triangle is not something that exists by itself. You know, that would be the Platonic mistake right? In the world of forms, right? But it's what it is as something of this individual triangle, right? And what it is, what a man is, or what a dog is, is that what it is of Rosie over there, right?

[54:34] Or what it is of you and me. I see. Yeah. And so we don't think about the what it is of a dog or a triangle without, in some way, imagining an individual dog or triangle. What we understand directly is the universal,

[54:58] the what it is. Next time we do Article Eight, and then we'll start on the next one here, right? Modus ordinarii intelligendi.