 The discussion that follows shall employ these categories in order to analyse the thought of ancient and medieval philosophers. Once again, this may be thought to run the risk of anachronism, insofar as such categories are not themselves ancient. Although one school of ancient thinkers did identify themselves as empiricists, no ancient or medieval philosophers made these particular distinctions. But this is not a fatal objection. We should not distort the thinking of ancient or medieval philosophers by forcing it into modern categories, as into a Procrustean bed. Nor should we write intellectual history in a “Whiggish” fashion, interested only in those features of ancient thought that anticipate our own. But as Allen Wood once remarked (a little too paradoxically), “people can mean things they can’t think, and therefore … must be able to express thoughts they can’t have” (A. Wood 2002: 227). When it comes to ancient and medieval philosophers, our modern categories can help highlight aspects of their thought they themselves may have been unaware of.