How Aristotle Thought about the World

If what you were trying to do was to get something to die, then a heart that pumped blood would be malfunctioning. In this video, I'm going to just introduce the worldview of arguably the most influential thinker in world history. And that thinker, of course, is Aristotle. So we're just going to get an understanding of how Aristotle thought about the world. And this became the dominant way of thinking about the world, at least in the Mediterranean and Europe, for, you know, a thousand years. It's a very different way of thinking about the world than the way that we have now, than the sort of scientific worldview that's common today. So let's actually start with the modern worldview. On our worldview, all of the stuff in the universe is made up out of smaller stuff, constituent particles. And the central features of these particles, the facts about them that we use to explain everything we see around us, these facts are quantifiable. Think about things like mass or velocity, right? These are features of particles, little stuff, atoms that things are made of. They're features that can be measured with numbers, with mathematics, right? If something has a certain mass, we can measure that mass with numbers. So the essential features of the little stuff that everything's made of, those features can be understood, best understood in terms of numbers, quantities. And also, these particles, these fundamental constituents of reality, they follow universal laws. This is how you think about laws of nature, right? The laws that govern atoms are fundamentally the same laws that govern planets. And for that matter, these laws apply everywhere, everywhere in the universe. The same law of gravity that tells you that, you know, if I drop this marker, it's going to go down, right? It's going to be attracted to the mass of the Earth. The same laws that govern a marker on this planet govern the moon and the sun and all of the stars in the galaxy and all of the galaxies beyond, right? The laws of these objects are universal. This is part of how you think about the world, because you are an adherent of the modern worldview. And the laws of nature, as we conceive of them today, they're universal not just in the sense that they apply everywhere, but that they apply to all sorts of different types of stuff. They apply not only to inanimate objects, massive inanimate objects like stars, but they also apply to the growth of organisms, to how a plant or an animal grows. All of these things fundamentally are part of the same natural order. You don't have separate laws that distinguish between one domain and another. The laws are universal. On the Aristotelian worldview, the way that Aristotle saw it and the way that millions of people saw it for well over a thousand years after Aristotle, following Aristotle, was that things were fundamentally understood, differences between things were fundamentally understood in terms of qualitative differences. Qualitative. Some different things had different natures. They just were a certain way, right? And these natures couldn't be measured in numbers, in quantities. There was just a certain quality that things had. And these natures, they were, we might say, domain specific. So they only applied to certain things in a certain domain, right? So there was the nature of a certain type of animal. And that explained why the animal did what it did and how the animal grew the way that it grew. But you couldn't apply that nature anywhere else. You couldn't apply it to plants or certainly not to stars or moons or anything like that. Aristotle even thought that the laws that govern everything that happens on the planet Earth are just different laws than the ones that govern the motion of heavenly bodies. If you think about it, Aristotle's worldview is the most rational one to adopt if you just opened your eyes and looked around at the world. Imagine that you were a cave person and you emerged from a cave and you were extremely smart. You were extremely smart, but you didn't have the advantage of all sorts of experiments and discoveries that had been made before you. You would look around at the world around you and you would see that certain things fall down to the ground and certain other things rise up like fire. Fire goes up, right? And then you look at the moon and the stars and you realize those things aren't falling down and they don't seem to be rising up. They just sort of seem to be like rotate around, right? And the Earth stays still. And so you would think, okay, well, the Earth is not moving. It's at the center. The sun and the stars and the moon, those are moving around. And those things up in the heavens, they don't follow the same laws that stuff does down here, right? That's what you would think. That's the rational thing to think if you have a limited data set. So anyway, the laws are domain specific. Things have a certain nature and those natures are understood qualitatively, not quantitatively. Now, Aristotle did think that things were made up out of elements, basic elements, constituent parts. And he thought that there were four elements. And you may have heard of these four elements. Here's what they were. This comes from Aristotle. This is well over 2,000 years old. There were four things that all the stuff around us is made up out of. Earth, water, air, and fire. Those are the four elements. And they combine in different ways, so thinks Aristotle, to make all the stuff, like a human being. A human being is made up out of a bunch of water and some air and some earth, right? And then also a little bit of fire or whatever, in a certain ratios arranged a certain way. And each of these elements, well, they have their own nature. But, and this is a crucial point, don't miss this. The stuff that's made up out of these elements, they've got their own natures too, right? So a human being has a nature in addition to the natures of all the constituent parts. And the nature of a human being for Aristotle, or of a lion, or of a tree, or of a rock, or of the moon or something like that, the nature of a larger object made up out of these elements, its nature is separate and can't be explained in terms of these. There's more to a human being than just the combination and arrangement of the elements of which a human is composed. That is very different from the way that we think about human beings today, from the modern scientific worldview. I mean, for one thing, there's a lot more than four elements, right? There's many elements and they're, well, they're invisible. Invisible. They're tiny. They're atoms or subatomic particles or something like that, right? We think that the world is made up out of atoms. And after that, out of protons and neutrons and electrons, and then out of quarks or whatever. But these things are all invisible. You can't see them. They can't be, well, Earth you can see, right? Everything on Aristotle's worldview is visible. On the modern worldview, there are these little tiny invisible elements that things are made up out of. And if you want to explain why a tree grows the way that it does, right, on the modern scientific worldview, you just look at the atoms that compose it and how those atoms interact and the quantifiable properties of those atoms, and that's it. You're done. You can explain everything about the tree. You can explain why the leaves are green and why they fall off when it gets cold in the winter. You can explain everything about everything in terms of the quantifiable universal properties of these constituent elements. On the Aristotelian worldview, that's not the case. You can't explain everything about a human being just from how much water and earth and air and fire are in the human being and where those elements are arranged. You need an additional nature, the nature of the whole thing. And the nature of that whole larger thing, a tree or a human or the moon or whatever, the nature of that whole thing can't be reduced to or explained entirely in terms of the elements that that thing is made up out of. So on the modern worldview, there's just matter. That's it. There's the stuff that things are made up out of, and that's all you need to explain everything. Just particles. That's all everything is. Everything is just particles. Whereas on the Aristotelian worldview, there's a combination of matter and also the nature or the form of stuff. And you can't just explain a tree, for example, by mentioning all of the atoms that build up that tree, all of the matter. You also need... Oh, well, I shouldn't have said stuff there. I should have said nature, the form or the nature of that thing. Here, let's just get rid of form. We'll go with nature. All right, I'm going to erase that. Okay, nature, right? So you've got the matter that makes up the tree. And then if you're going to explain on Aristotle's worldview why the leaves fall off in the winter and why the leaves are green, and then they turn red and why the trunk grows a certain way, you have to appeal to just the nature of the tree. That's just what trees do. It's in their nature that they grow big and tall, straight up towards the sky, right? And that fact about trees, well, that they have a certain nature, that they function in a certain way, that fact can't be measured with numbers. Okay, so it should seem already like there's a huge difference between the way that we think about the world today, the scientific modern worldview, one that emerged in the, I don't know, 16th, 17th centuries, 18th centuries, right? There's a difference, a huge difference, between the modern scientific worldview and the Aristotelian worldview that dominated beforehand. And if you're really going to understand Aristotle's worldview, the most important idea is the idea of things having a certain nature. The nature of a thing, for Aristotle, that explained not only what that thing did, but what it ought to do. So once you understand the nature of a human being, for example, you understand not just how humans behave, but how they ought to behave. What you get out of the nature of things is a certain kind of morality. You can just figure out the moral state of affairs of the universe from understanding, well, the sort of scientific state of affairs of the universe. That's very different from how we naturally think on the modern scientific worldview, right? On this worldview, well, how things ought to be is just sort of a separate matter from how they are. Just, if you know about where all the atoms and all the human beings are, and you know how people do behave, that doesn't itself tell you how they should behave. You need to figure something else out if you want to figure out how things should behave. If you're religious, for example, then you think, maybe, that facts about how people should behave come from God. That's how you figure them out. You ask God, and you check his book, that sort of thing. Or if you're not religious, then you're going to have some other story that you're telling about where the moral facts come from. They don't just come from the sort of natural state of affairs. On Aristotle's view, they do. One way to think about how these ought facts, how these facts about how things should be come from the nature of a thing is just to think that things have built into them on Aristotle's worldview a function or a purpose. It's just built into a tree that its function is to become big and sturdy and tall. That's the purpose of a tree, is to become big and sturdy and tall. If a tree is really flimsy and short and stubby or whatever, then it's failing in its built-in purpose as a tree. Whereas on the modern worldview, trees don't in themselves have purposes. They just sort of grow the way they do. Sometimes they grow big and tall and sturdy, and sometimes they grow sort of flimsy and small or whatever. A big sturdy tree is good for some stuff, and a short flimsy tree maybe is good for some other stuff, but it's not like built into the tree on the modern scientific worldview, there's a function or a purpose or a thing that the tree is striving to be. On our view, any kind of function of anything, it comes from a mind. We impose functions on things. Say that I took a rock and I placed it in the middle of an area, and I used that rock as a table. Okay, so now that's the function of the rock, is to place things on and eat off of or whatever, or I can sit down and write on it or whatever, right? Now this big rock has a function. I gave the rock its function. That's how we think of all functions. They're imposed by minds. If you think that human beings have a function, if you hold to the modern scientific worldview, which I think you do, if you hold to the modern scientific worldview and you think that human beings just have a function, then you probably think that they were given that function by a deity, for example. Well, that's just a mind. If God exists, or gods, if gods exist, then God or all the gods, they're just minds. They're consciousnesses. Maybe they're more powerful consciousnesses, and better ones, benevolent ones, all-knowing consciousnesses, but they're minds, and they give human beings their functions just the way that a human being can give a rock a function as a table. On Aristotle's worldview, things just have built into them certain purposes or functions. Okay, so I've explained the Aristotelian worldview and how it is different from the modern scientific worldview. The last thing I will do is sort of defend this claim, this claim about the modern worldview, from a potential objection that might occur to some folks. We do often say things like the following. The function of the heart is to pump blood. That's, well, the heart is a thing, you know, the heart. It's a, here, I don't really know, okay. The heart has a certain purpose or a certain function, namely, to move blood through the body. Aristotle can handle that. Aristotle can say that some object has a function, but I just said that things don't have functions built into them. But we do say this. Adherents of the modern scientific worldview do say stuff like this. How could that be? Well, there's a few things. The first thing is that I actually think that this is, when properly understood, just sort of a shorthand or an abbreviation for some facts about natural selection. So, strictly speaking, the function of the heart isn't to pump blood. The heart doesn't have a function, really, not built into it. No. What happened is that some organisms, they started having hearts. And the hearts just did a thing. It's not like it was their function to do it. They just did pump blood around. And it just so happened that the organisms that moved the blood around were better able to pass on their genetic material and the species of which they were a part thrived and procreated and whatever, right? So the heart serves a function within an organism in the sense that it allows that organism to continue living and procreate and move around and all that sort of stuff, right? But, well, we only think of a heart that pumps blood as properly functioning because we think that living is good. And I'm not saying that it isn't. Living is good. Survival is good. But it's only because we think that that we think that a heart that's pumping blood is functioning properly. If what you were trying to do was to get something to die, then a heart that pumped blood would be malfunctioning. The other crucial difference between this way of talking about the function of the heart and Aristotle's view is that even if we do think that there are some functions that are built into certain things, we never, on the modern world view, go directly from this sort of function to any ethical or moral conclusions. We never do that, right? You can't conclude from some fact about the function of the heart that hearts or people should act a certain way. So that's something that only Aristotle has access to. Okay, so that's the whole story. That's the whole video. That's everything I wanted to say about the difference between the Aristotelian world view and the modern world view. If you're understanding what I've said so far, you realize that Aristotle's way of thinking about everything is radically different from the way that we think about things today.