Aristotle on Metaphysics(2004) - Bibotu.com

186 PHENOMENALISM AND RELATIVISMwhich merely state the causal realist theory of sense perception, are only asummary statement of <strong>Aristotle</strong>’s theory of sense perception, which hedefends carefully and at length, especially in the De Anima. So these fewlines are evidently not supposed to be the last word.But if we look a little further (than the end of IV. 5), we see that it maynot after all be <strong>Aristotle</strong>’s aim to base the defence of PNC-M solely on thecausal realist theory of sense perception. Rather, his aim is to present thedisputant of PNC-M with the following challenge: how will he, thedisputant, want to explain why PNC is true at least of things as theyappear to us, and why at least things as they appear to us are determinate?How will he do this, if not by arguing that PNC is true of the thingsthemselves and that the things themselves are determinate? The latterexplanation is, of course, <strong>Aristotle</strong>’s, and it relies on the causal realisttheory of sense perception. So the challenge is this: does the disputant havea better explanation of why PNC is true of things as they appear to us, andwhy things as they appear to us are determinate?Thus shortly after the passage at the end of IV. 5 (i.e. in IV. 6, 1011 a 31-b 1) <strong>Aristotle</strong> emphasizes that even those who argue that the thingsthemselves are radically indeterminate, and that PNC is not true of themand it is not possible to think or speak of them, must admit that PNC is atleast true of things as they appear to us and our senses, and that at leastappearances are not radically indeterminate; and they must admit this evenif they defend an extreme form of relativism. For example, they mustadmit that if something, at a particular time, appears red to one’s sight, orto one’s sight in a certain respect (e.g. to one’s left eye), then it does not, atthat particular time, appear not-red to one’s sight, or to one’s sight in thatparticular respect (e.g. to one’s left eye). But how will those who denyPNC-M, and who claim that the things themselves are radicallyindeterminate, explain why PNC is true at least of things as they appear tous, and that at least things as they appear to us are not radicallyindeterminate? <strong>Aristotle</strong> provides an explanation: it is because the thingsthemselves are determinate, and PNC is true of them, that the things asthey appear to us are determinate and PNC is true of them. But evidentlythis explanation will be not acceptable to the disputant of PNC-M. So itappears that the disputant of PNC-M must argue, on the one hand, thatthings as they appear to us are determinate and that PNC is true of thembut, on the other hand, that this determinacy does not require furtherexplanation, i.e. it does not require an explanation that appeals to anythingother than the things as they appear to us. But this, in effect, amounts tothinking that the things as they appear to us are determinate in virtue ofthemselves and not in virtue of their relation to other things—and in