Transcript Reading: Hume Part 2

We’ve reached the point where we see that Hume has reduced everything in his philosophy to ideas or impressions. An impression is a present sense sensation—it’s a sight, taste, touch, sound, or smell. Ideas are copies of those impressions, the afterglow of the impressions, allowing us to remember or conceive of them, or both. And there is nothing else in the mind. If that’s true—and Hume is arguing that it is—then he repeats Barclay's reduction argument: all the things we think are physical, upon analysis, turn out to be just bundles of sense perceptions. So Hume accepts this as true and then raises other questions. One of those questions is about how these ideas relate to one another in the mind. He wants to answer that first before moving on to other questions, such as the mind itself—what sensation corresponds to the idea of the mind, if you're strictly following his rule. He’s also going to address the problem of the external world.

Here’s Hume in his own words: “There are certain principles that connect ideas, and these are: (1) resemblance, (2) contiguity, and (3) cause and effect. These three principles serve to connect ideas and will not, I think, be much doubted. A picture naturally leads our thoughts to the original of which the picture is made. A painting brings to mind the objects painted.” That’s resemblance—the picture is supposed to resemble the objects it portrays. So that’s the first relation ideas have.

Another example: “The mention of one apartment in a building naturally introduces an inquiry or discussion about the other apartments in the building.” This is contiguity—discussing an apartment in a building brings to mind the other apartments.

The third is what he calls cause and effect: “If we think of a wound, it brings to mind the pain.” These are natural associations ideas can have with one another—associations that happen without our willing it. Together, they make up the law of association of ideas.

This is not law in the sense of the natural laws of physics, space (like geometry), mathematics, or logic. Hume is not placing these in that category at all. The law of association is a free-floating kind of thing that can take place or not. These three are the natural associations.

Now, there are artificial associations, too—ones we can make happen between ideas. His list includes resemblance, identity, space and time, quantity, degrees of quality, cause and effect, and contrariety (things being contrary to one another). So, all the natural ones are on this list, but we can also make any of them happen at will or not. They can happen whether we will them or not, but the others are ones we deliberately make happen.

And those are, as I just read them: identity, space and time (which refers to before and after, ahead and behind, and so forth), quantity or number, degrees of quality, and contrariety. It’s the natural associations plus those, and we can bring those about. We can deliberately compare two ideas in these non-natural, artificial senses, just as we can compare them in the three natural senses. Altogether, they constitute the law of association, which is the only law that governs sensations.

We’re not looking for laws as we find them in physics, geometry, or astronomy. Those laws are mathematical, fixed, universal, and they apply all the time without exception. These are rough rules of thumb—observations about how perceptions can relate, either naturally or by our will.

Hume then deals with the problem of abstract ideas. Normally, we think there are abstract ideas. For example, we can have an idea of this person, that person, and another person, and then form an abstract concept like "human" that covers all people. This is a problem for Hume.

“When we have found a resemblance among several objects that often occur to us, we use the same name for all of them, whatever differences they may have. After we’ve acquired the habit of this kind, hearing that name revives the idea of one of those objects, and makes the imagination conceive of it with all its particular circumstances and proportions. When we hear the word again, we think of a particular individual—we don’t have an abstract idea or a picture of humanity in general.”

The same word has been frequently applied to other individuals who are different in many respects from the specific idea I have when I hear that term used. The word doesn’t revive the idea of all the other individuals. Instead, it “touches the soul,” and, if I may put it this way, revives the custom we’ve acquired by seeing them. The word raises up an individual idea along with the habit or custom. It’s certain that we form the idea of individuals whenever we use a general term, and we can seldom or never exhaust the individuals it refers to. They’re only presented by means of the habit we have acquired.

So here’s his answer: when we hear an abstract, general term like "human" or "automobile," the only thing that forms in our minds is a picture of a particular one. But we know that when we use this abstract, general term, we intend for it to cover everything alike in being of this type. So, when we use an abstract term, we think of a particular thing, but we remember that the term is meant to stand for the entire class of things, for all individuals who are humans or automobiles. That combination of a specific individual and the memory of the general use of the term creates what looks like an abstract general idea. But really, it's just a specific term plus the memory that we want to use it in a general way. That's it—there is no abstract, general reality. There is no "what it is to be a human" beyond humans, or "what it is to be a car" beyond cars. Here, Hume is running against nearly all his predecessors.

What about the idea of substance—the idea that some kind of reality underlies all the properties we perceive things to have? Here are Hume’s own words:

“I would ask those philosophers who base so much of their reasoning on the distinction between substance and what depends on it—and imagine we have clear ideas of each—whether the idea of substance is derived from an impression or sensation. If it is conveyed to us by our senses, I ask, by which sense? In what manner do you see substance? What color is it? What noise does it make if we drop it? How heavy is a piece of substance? If it’s conveyed to us by our senses, I ask, by which sense? If it’s perceived by the eyes, it must be a color; if by the ears, a sound; by the palate, a taste, and so on. But I believe no one will say that substance is a color, sound, or taste. Therefore, the idea of substance must be derived from an impression of reflection. We reflect on those sensations and come up with this idea, if it really exists. But the impressions of reflection resolve themselves into passions and emotions, none of which can represent a substance. We have, therefore, no idea of substance distinct from that of a collection of particular qualities, nor have we any other meaning when we either talk or reason concerning it.”

Descartes spoke of rational and physical substance. Locke said there are physical substances that make up the world outside ourselves. Leibniz got around this by saying the substances are monads—combinations of them can fall apart, but monads can’t be destroyed. And anyway, monads are solitary individuals with no windows. But Hume presses the question: If you talk about substance, tell me what impression gave you that concept. If it’s no impression, it must be an idea of reflection—but those are emotions. Which emotions correspond to substance? The answer is none, and therefore the idea of substance has no meaning at all.

What about the human self? How does he treat that? Remember, Barclay tried to escape some difficulties by saying, “I have an intuitive notion of myself, my mind. Since my mind perceives, wills, and feels, I can conceive of another mind that does the same without limitation—thus perceiving everything all the time. That’s how I justify the idea of my mind and also the concept of God.”

Hume responds: “For my part, whenever I enter most intimately into what I call myself, I always stumble upon some particular perception—of heat or cold, light or shade, love or hatred, pain or pleasure. I can never catch myself at any time without a perception, and I can never observe anything but perceptions. When my perceptions are removed for any time, as by sound sleep, I may truly be said not to exist. And were all my perceptions removed by death, and I could neither think nor feel nor see nor love nor hate, I should be entirely annihilated. Nor do I conceive what more is required to render me a perfect nonentity.”

So, here’s his answer: Whenever I look inward, I don’t find some other thing called the self. I’m not able to observe my mind as though it’s a little room where these things occur, with walls I can see apart from the things that come through them. No—I have some present perception or some idea of a past impression, and that’s all. If I were without all perceptions, I would cease to exist. In other words, the mind isn’t a separate thing that observes the perceptions—the mind just is the perceptions. There is no physical substance, and there is no mental substance.

The mind is a kind of theater where several perceptions in succession make their appearance, pass, repass, glide away, and mingle with an infinite variety of other perceptions and situations. There is, properly, no simplicity or identity at any time. Whatever natural inclinations we may have to imagine simplicity and identity, the comparison to a theater must not mislead us. It is the successive perceptions only that constitute the mind. Nor do we have the most distant notion of the place where these scenes are represented or the materials that compose it. It’s not a distinct thing made up of particular materials, dimensions, and so on. No, the mind isn’t a thing; it’s just the name we give to the collection of all the perceptions and ideas we have. Radically, there is no physical, no material substance, no mental substance—there are just perceptions.

I want you to hear more of what he says about the external world. Now, we all naturally believe that when we use our eyes, ears, fingertips, noses, and taste, we’re perceiving the world around us. It’s our Lebenswelt, our life-world. But then we begin to reason about it, and if we follow these guys, what we experience isn’t the real world around us—it’s just stuff happening inside here, in our minds. And we have to explain how we get from the stuff inside to believing in an external world.

“The mind never has anything present to it but perceptions and cannot possibly reach any experience of their connection with objects. The supposition of such a connection is without foundation, and reasoning can't be plainer. We know the objects that are in our minds, but our minds are actually just those objects—impressions and ideas, perceptions, and concepts or memories of them. That’s it. Can we show that these are all produced by things outside us? No, we can’t. They enter only into the relations we saw before, and we can’t even say that there’s a mental substance.”

Hume had to admit that there were problems with that account. Remember when I read to you where he said, “Whenever I enter most intimately into myself, when I introspect, I find only some present impression or a copy of a past one.” He admits that when the second edition of his book came out, a woman wrote him a letter and said, “But what is the ‘I’ that looks into myself doing?” He had to write back, “I don’t know.” That’s not a very good answer. In fact, it’s no answer at all—there’s something substantial doing something. Hume says there isn’t.

He talks again about whether there’s an external world: “That our senses do not offer their impressions as impressions of something distinct and independent outside themselves is evident because they convey to us nothing but a single perception, and never give us the least intimation of anything beyond them.”

My reaction to that? Let’s just say balderdash! That’s plain, flat-out wrong. He’s telling me that all the sensations I ever get don’t have any inclination, don’t present themselves to me as copies of an external world? They certainly do—that’s exactly what they do for everyone, everywhere, unless they’re seduced by arguments like Hume’s. I need reasons to believe there are such things as perceptions and not such things as trees, clouds, mountains, roads, and other people. I experience these things as objects independent of me, external to me, and different from me. And when I ask how that works, I may start talking about abstractions like perceptions, but I don’t ever see a thing called a perception. What I see are mountains, clouds, roads, people, the desktop, chairs, etc.

So, for Hume to say, without reason, that the impressions we receive don’t present themselves as distinct from other things and that those other things are external to them—I’d say, we don’t have impressions then. There are no such things as perceptions. There are just people and our awareness of other objects. Perceptions are constructs of an attempt at a theoretical explanation of what we perceive. He’s put them as the primary thing and said, “We don’t know the reality that prompted us into all this thought in the first place.” No, I won’t let Hume or anyone else get away with that.

He continues: “It may perhaps be replied that our own body evidently belongs to us. As several impressions appear exterior to the body, we suppose they are exterior to ourselves. Do you think the paper on which I write at present is beyond my hand? The table is beyond the paper, the walls of the room are beyond the table, and in casting my eye toward the window, I perceive the extent of fields and buildings beyond the room I’m in. From all this, it may be inferred that no other faculty is required besides the senses to convince us of the external existence of real things.”

But to prevent you from drawing that inference, Hume offers three considerations. The first is that, properly speaking, it’s not our body that we perceive. When we perceive our limbs or other parts of our body, there are only sense impressions that enter through the senses. So, ascribing a real bodily existence to those impressions, the objects we perceive, is an act of the mind that’s difficult to explain—but Hume says he will now undertake to do so.

Why does everyone naturally think that when they see a tree, it’s really there? My reply is that normal sense perception presents the world around us as self-evident. If we remove the three restrictions that Descartes tried to put on self-evidence—namely, that everybody has to agree with you, it has to be a law, and it has to yield infallible truth—then I think each one of those restrictions is false. We don’t have to have everyone agree with us. Not everyone has to know every self-evident truth—that’s arbitrary, made up, and there’s no justification for it. If you ask, “How do you know that everybody has to agree?” you won’t get an answer. How do you know that self-evident truth must be necessary and lawful?

Why should we dismiss normal sense perception when that’s the most obvious? Why should we dismiss the self-evident truth of God’s Word and God’s reality when we experience that, just because it’s not a law? Not all laws are self-evident, and not all self-evident truths have to be laws. There’s no good reply to that either. And why should self-evident truth yield something infallible? That doesn’t follow. The closest things we have to infallibility are reports of our own internal states. 

If I say my stomach's upset tonight, it's hard to see how I can be mistaken about that. I could lie about it, but I can't be mistaken about it.

I have this ache in my right knee that just won’t go away. How can I be wrong about that? So, the nearest things we have to being unable to be wrong are our own internal states—things we know by introspection—but none of them can be verified by everybody, only by me. I alone know whether I'm lying or reporting a real ache. So, they violate the "everybody" requirement, and the fact that I have an ache in my right knee isn’t a law. So, the best candidates for knowledge that we can't be mistaken about contradict the other two requirements. Don't be deceived—there's no good reason to dismiss the self-evidence that attaches to normal sense perception. Is it infallible? No. I can be fooled. Occasionally, optical illusions could deceive me, or I might experience hallucinations or holograms. But I discover these deceptions through more and better sense perception.

Let’s go back. Hume is going to go through his reasons why the natural inclination of everybody to regard what they perceive as real doesn’t yield the truth. First, he says, it’s not, properly speaking, our body that we experience, but sensations of our body. That begs the question. Second, sounds, tastes, and smells, though commonly regarded by the mind as continuous, independent qualities outside ourselves, appear not to have any existence in extension, and consequently can’t appear to the senses as situated externally to the body.

I don't know how he can say that. I can certainly find a smell concentrated in just one corner of the house and wonder what's causing it. Everywhere else in the room, it’s fine, but right over here, it's distinct. If I peel back part of the wall and find a dead rat, I'll know what caused the smell. Sure, it’s extended. That’s like saying ideas can’t exist in space. Well, then there’d be no such thing as a secret. Nothing could be known in one place and unknown in another, and spies would be pointless.

Okay, let’s continue. Hume says sounds, tastes, and smells do not have extension in space. Surely they do. Even our sight doesn’t inform us of distance or “outness,” so to speak, immediately and without some reasoning and experience. And this, he says, is acknowledged by the most rational philosophers. Well, I don’t care who acknowledges it—it’s a mistake. It’s the exact opposite of what we actually experience, which is that everything around us—external objects—are really there. That’s confirmed by our sense of touch, sound, smell, and taste. In fact, when it comes down to it, we trust our sense of touch the most, don’t we? If I see an object in front of me, try to touch it, and my hand goes through it, I’d assume I was hallucinating or being deceived by a hologram. But if I didn’t see an object and every time I tried to move my hands they hit resistance, and I could feel an object but see nothing, I’d believe it was real but invisible.

We trust our sense of touch even over sight, and yet even the sense of touch can be deceived.

For instance, someone addicted to alcohol may experience delirium tremens (DTS), where they feel snakes crawling all over them, insisting that the doctor just doesn’t see them. They believe the snakes are real because they can feel them. We trust touch over sight, but even touch can deceive. The person doesn’t really have snakes crawling all over them. Hume knew about these things. Delirium tremens didn’t just crop up in the 21st century. These guys knew all about it.

Hume is preaching this notion that there are three reasons why, even though we may habitually regard things as outside and independent of ourselves, they’re not really external. First, he says, we don’t perceive our bodies—we only perceive the perceptions we call our bodies. Second, sounds and tastes aren’t extended spatially as external objects should be. Third, even our sight tells us that the “outsideness” we take for granted is just a habit we’ve developed. For such a sharp thinker, this reasoning is poor.

In contrast to Barclay’s notion that things are objective because many different minds can have the same perception (with God providing each person’s perceptions), Hume offers no such explanation. Barclay would say that if I perceive a door from one angle and someone else perceives it from another angle, God ensures we both perceive the same door according to our perspectives. Hume can’t explain this. He says there are no minds, no external objects—just sensations and ideas. He dismisses the common belief in the external world as arising from a habit.

Hume’s answer is that the faculty of imagination is at work. It imagines things as external and independent, and we habitually follow this imagination rather than the way things really are.

I enjoy finding these pithy sections in Hume where you can hear him defend his ideas about external objects. But Hume also says something important regarding his purpose. Hume admits that 10 minutes after people read his critique of the external world—why we can’t really know such a thing—everyone will go back to believing in objects. They’ll revert to thinking there’s really a door over there, external to themselves and existing independently of any perception of it. He knows that.

So, what’s the point of his arguments? Why go through all this work, explaining away the objects we perceive, the minds that perceive them, and of course, dismissing God? (If there are no minds, we don’t have a concept of mind. If we have no concept of mind, there’s no infinite mind or infinite spiritual being with all perfections. God goes too. There are no sensations corresponding to perfect goodness, perfect justice, perfect mercy, or omnipotence. All you do is think of a specific instance of something good, just, or powerful, and when you try to imagine it without limitations, you lose the idea. You can say “without limitations,” but that’s not what’s in your mind. What’s in your mind is this specific act of goodness, justice, or power with all its limitations. And if you take the limitations away, you lose the idea entirely.)

So all of this—God, perfection, and everything else—goes into the philosophical garbage heap, not to be taken up again. But what is Hume’s purpose? And here’s the surprising part: Hume says, “I know that 10 minutes after you read all these arguments, you’ll go right back to believing in objects, and that’s only as it should be.” What this shows, according to Hume, is that human beings are not primarily rational beings. He’s doing this to show the futility of philosophy and reasoning. If you strictly stick to reason and your own definitions, you end up with nothing because human reason isn’t meant for this kind of thing. That’s his claim—humans are not rational animals. And that’s been the definition of humans ever since the ancient Greeks.

What's the difference between humans and other animals? Descartes and, I’m sorry, Aristotle’s answer is reason. Humans can think abstractly. They can come to know the laws of nature, invent theories to explain things, and do philosophy and science. That's their main difference. They have an animal nature that's emotional, and what they need to do is bring that nature under the control of reason. Plato and Aristotle had different ideas about how this works. For a long time, this has been the dominant definition of what it means to be human, and Hume wants to challenge this.

Hume says humans are emotional animals. They're driven by their feelings and desires. Reason only shows them how to achieve those desires, but emotion sets a person’s goals and aims. People don’t reason about what they should do in life or whom they should marry—they fall in love. And virtually every language has an expression equivalent to that. You don’t choose who you fall in love with—it’s something you can’t help. You don’t reason your way into it. The same goes for believing in external objects. You don’t reason your way to them. You don’t set up a theory, go through the steps of a logical argument, and conclude that there are real external objects. No, Hume says, if you stick strictly to reason and current theories—the best knowledge we have—you end up with no external world, no mind.

What does that show you? Don’t waste your time with philosophy. Hume says, “When I think about that, I know I’d be better off just playing another game of backgammon. I like that game.” That’s his conclusion: humans aren’t made to figure out the world or how they work. Reasoning powers only help them achieve their goals, but emotions set those goals. That’s the view he takes. All his arguments, his reasoning, and his defeats of other philosophers aim to show that humans are not primarily rational animals.

So, we’ll have another session on Mr. Hume, focused on his ethics. He didn’t write about politics, but he did write about ethics. How, and under what circumstances, do we know that something is right or wrong? He picks up where Locke left off, talking about pleasure, pain, and how we form ethical rules. When we read Hume, we see that we are locked inside ourselves, unable to know the external world, and unable to know our own minds. According to Hume, we can’t even know right and wrong—there are no hard and fast rules about good and evil.

Kant is going to be incensed by this. If we let Hume get away with dismissing rationality and reducing humans to emotional beings, it’s the same as throwing all the sciences into the toilet and flushing. Kant isn’t going to stand by and let that happen. No, we can know certain truths that are laws. Remember, for Hume, there are no...

Let me try that again another way. Oh well, we’re not going to use the board anymore today—it won’t take the stylus. For Hume, there are no general, abstract ideas. There are no universal truths. We can’t know that something is always true. “One plus one equals two” is true because we define it that way, Hume says, not because it’s inherently true in the larger reality. Are there ever exceptions? How would we know, since we can’t experience everything?

I remember one time when I was about 10 or 11, I asked my mother, “Are ten tens really a hundred, or do we just say that they make a hundred?” She looked at me very puzzled, and now I understand why.

As far as Kant is concerned, Hume has all the wrong answers. Kant is going to save science, which for him mainly means astronomy and physics. He’s going to save ethics, too. We can know ethical rules, and we can know them with certainty, just as surely as we know the laws of gravitation, free fall, or planetary motion. And Kant will say to Hume, “Go ahead, show me what you’ve got.” And Kant is going to show him.

We’re going to start where Hume and Locke thought was the right place to begin—by investigating the architecture of the mind. Hume used the term “mental geography,” the layout of the mind. What powers does the mind have, and how do they work together to produce what they produce in us? Kant is going to start with that.

So next time, we’ll cover Hume’s ethics and an introduction to Kant. That’s what’s on the docket for our next meeting.