There are for Ockham, as was just said, no universal substances. There are only individual substances. Such individual substances, then, are realities, whereas universal substances are concepts. For Ockham, some qualities are also realities. However, some are not. If the grass you see is green, it is because green is an inhering quality of the grass. If two white men are white, each has whiteness as a quality in them. They are thereby also alike or similar to one another insofar as each is really white. Yet, even though they are really alike according to the accident of whiteness that each has, this does not mean that there is a quality of ‘‘likeness’’ in them. Twins also are alike, really and essentially alike, because both are human beings; but they do not have ‘‘twinness’’ in them as an inhering real quality expressing that they were born of the same mother within a short period of one another. Men also are really tall and really short, but when we speak of the tall one being taller than the short one, the relation between them does not demand that we admit a quality of tallness in a man whom we might describe in common parlance as ‘‘really tall.’’ When, then, we deal with the Aristotelian categories and want to speak scientifically or precisely, we have to ask for what realities do our terms expressing substances, qualities, quantities, relations, and the other categories supposit. They do not all supposit for directly corresponding realities.
World History
