[MUSIC] We are now in a position to see why Parmenides objects to the notion of change. We must reject the notion of change, he argues, because thinking about change involves thinking about what is not. And that's the root of inquiry that is forbidden to all rational thinkers. We've already considered what he thinks is wrong with thinking about what is not. Now let's consider change and see how it involves what is not. Fragment B8 is our main text here, which opens by telling us that if we stay on the right path, the path of is, we will have to agree that what is, that's what we're allowed to talk about, is ungenerated and imperishable. That is, whatever there is does not come to be or cease to be. Okay, that's Parmenides' conclusion. But what is his argument? If we read on, we see that Parmenides appeals to what would have to be the case if something does come to be. For what birth will you seek out for it? How, and from what, did it grow? That is, if something comes to be, or becomes, that's the same word in Greek, it must come to be from something. Now he gets to the punchline. That something is the dread, what is not. He says, from what is not, I will allow you neither to say nor to think, for it is not to be said or thought that it is not. So here's how we can reconstruct Parmenides's argument. First step, if something comes to be, it comes to be from what is not. Second step, we cannot think about what is not. Third step, so change is unthinkable. So we have seen Parmenides' reasons for maintaining the second step. But why should we accept the first premise? Why suppose that coming to be has to be from what is not? Here's the general idea. When a change happens, there must be a before and an after. First I'm a child, then I'm an adult. At one moment the room is empty, and another it's full. A century ago you did not exist, yet now here you are. In all of these changes, or happenings, what happens, or becomes, goes in the after column. And what it comes to be from, goes in the before column. Consider the change we call, growing up. Here I am, an adult, so we can put that in the after column. The adult is. Parmenides asks, you say this adult has come to be, yes. So there is an adult now, but this wasn't the case before. Yes, so we have to put in the before column, the adult is not, one of those dread is not claims. Now we can do the same thing for ceasing to be or perishing. As in a hundred years from now I won't be any longer, nor will you. So we will have to write that the adult is not in the after column. Once again, something unthinkable according to Parmenides. So in sum, Parmenides' objection to change, is that change is either a case of coming to be from what is not or perishing into what is not. So, change is inextricably bound up with the forbidden route of trying to think or speak about what is not. In other words, change is a fundamentally incoherent notion. So what's a naturalist to do when faced with Parmenides' argument, give up on the project of naturalist inquiry? Even Parmenides isn't prepared to go that far, for after giving the arguments that we've been considering, he proceeds to offer his own version of a naturalist cosmology. Which is full of coming to be and perishing. Look at fragment B19 which occurs at the end of that cosmology. In this way, according to these things have grown and now are and afterwards after growing up will come to an end. Lots of changes invoked here. But note the disclaimer about opinion, doxa, which he has branded in other contexts as deceitful and untrustworthy. Now opinion is contrasted with knowledge. A theme to which we will return when we study Plato. For Parmenides, knowledge and truth lie along the austere path of the is. While cosmology, which partakes of both the is and the is not, lies along the path of mortal opinion. Of those, who in his phrase are born along deaf blind alike. Dazed, hoards without judgement for whom to be and not to be are thought to be the same and not the same. And the path of all is backward turning. Note the dig against Heraclitus at the end of that quote. So Parmenides does not himself give up the project of naturalist inquiry. We can't help ourselves from believing in a changing world and from constructing theories about it, he seems to be telling us. However he does insist that there is no knowledge to be had from such inquiries. Naturalist cosmologies know less than Homeric poems are a kind of fiction. This is an effect to deny naturalist inquiry the status of science. Later naturalists, however, want to defend the scientific status of their inquiries, their claim to be seeking knowledge of the natural world. So they have to come to terms with Parmenides argument. By and large they agree with Parmenides that coming into being from what is not is unthinkable or unintelligible. But they aim to explain natural changes in such a way that they are not cases of coming into being, from what is not. So, which premise of Parmenides' argument do they reject?
