[MUSIC] We have seen that Aristotle thinks the most fundamental realities are the subjects for everything else that exists. Substances are the subjects for the qualities, quantities, activities, and so forth that in hearing them, and particular substances like Socrates and Fido are the subjects for the universal, such as human and animal that are said of them. So concrete particular objects like you and me, and presumably also things like tables and chairs end up being the most fundamental realities in Aristotle's ontological schema, according to what we might call the subject test for substance. This is why Aristotle calls these things primary substances. Chapter five of the categories explores some of the other features that distinguish substances from inherent items such as colors and sizes. And the distinguished primary substances like Fido from universal substances like dog. Aristotle calls these universal substances secondary substances. What he emphasizes here, as most distinctive of substances, and of primary, as opposed to secondary substances, is that they are able to, as he puts it, receive contraries. Here's what he says. It seems most distinctive of substance that numerically one and the same thing that is a particular is able to receive contraries. For example, the color that is numerically one nd the same That is a particular color. Will not be pale and dark, but a substance, an individual man for instance becomes at one time pale, at another time dark. For example, consider Fido's color which is dark brown. It being the particular color it is, couldn't be lighter or darker. Now when Fido gets old and gray, his color will lighten. But that's a loose way of speaking, according to Aristotle. It is not the particular color, which is dark brown, that has become lighter or grayer. Dark brown is still dark, rather, Fido will have changed from being dark brown, to being a lighter, grayer color. Colors are the sorts of things that can be lighter or darker, but they are not the sorts of things that can become lighter or darker. The same thing goes for all the other things that inhere in substances, according to Aristotle. It is the substances, not the inherent items, that get lighter or darker colored, larger or smaller, and so forth. This ability to receive contraries while remaining numerically one in the same is most distinctive of substance, Aristotle claims. Can you think of a counter example? Something that is not a substance but that can have contrary properties. Apparently, someone at the back of Aristotle's classroom thought they could. Aristotle records the objection in chapter five, and it goes something like this. Statements and beliefs, which are not substances, nonetheless can receive contraries. For, when Socrates is sitting down, the sentence, Socrates is seated, is true. And, when Socrates gets up, and goes for a walk, the same sentence is false. So, the same sentence can go from true to false. So substances aren't the only things that can receive contraries, sentences can do so as well. What do you think of this counter example? Has numerically one in the same statement changed from true to false? Aristotle doesn't think so. To say that the sentence has changed it's truth value, is just a loose way of speaking. As when we say Fido's color has changed. When it's not strictly speaking the color, but Fido that has changed. Rather what's really changed in the sentence example is Socrates, who has gone from sitting down to standing up and walking. While the statement has gone from true to false, this is just an elliptical way of talking about a change that is taking place somewhere else. Here's a way to think about it. Suppose a neighbor of Socrates writes on a wall in an obscure corner of Athens, Socrates is seated! And then sits down to keep a close watch over this message for the rest of the day. Meanwhile elsewhere in the city, Socrates sits down for breakfast making the wall writing true, then gets up and goes for a walk, making it false. Then he arrives in the Agara and sits down to have a conversation. After which he walks to the where the assembly meets, and he sits down to listen to speeches but jumps up to applaud his favorite speaker every few minutes. Think about all the times during the day that the wall writing has gone from true to false and back again. Especially that rapid oscillation when Socrates is applauding the speakers. Was anything happening to the wall then or to the writing? If we asked our observer who has been keeping an eye on the wall writing, whether it's changed at all during the day. The answer would be no nothing is happening to it. Nonetheless, that sentence, that wall writing was going back and forth between true and being false. These transitions are undetectable to the wall observer, not for want of fancy equipment and to detect changes invisible to the naked eye. But rather, because the wall and the writing on it are not changing. The changes that make the writing true and then false, are happening in a completely different part of town, where Socrates is. Socrates is the thing that is actually changing, not the statement that his actions make true or false. Okay. To get back to the main point which is the distinctive features of substances for Aristotle. The morale of our story here is that substances are not only the subjects of predicates but they are also the subjects of change. Primary substances, particular concrete individuals like Socrates and Fido are not only the most fundamental entities in the world. They are also subject to the changes that happen in the world. And this status as subjects of change, is one of the marks of their status as substances. Note how far we have come from the platonic picture. Plato accepts what we might call the Heraclitean view of the natural world, the world we experience. That is, he agrees that it is full of change but he thinks the truly real beings, the forms, are not part of the changing world. But are beyond it, in some intelligible Parmenidean realm, where there is no change. Aristotle, by contrast, has located his fundamental realities within the natural world, and selects as their most distinctive feature, that they are the subjects of change. We will turn next to study Aristotle's natural philosophy, where he presents his own solution to the Parmenidean problem about change, but also runs into some ontological difficulties as a result.
