Aristotle has just finished discussing identity and showing that predicates (or dialectic questions) can be divided into four categories: definition, property, genus and accident. Now he will show that each of those four categories are applied to ten different categories of predication. He does this in Topics, Book 1.
Next, then, we must distinguish between the categories of predication in which the four above-mentioned are found. These are ten in number: What a thing is, Quantity, Quality, Relation, Place, Time, Position, State, Activity, Passivity. For the accident and genus and property and definition of anything will always be in one of these predications- for all the propositions found through these signify either what something is or its quality or quantity or some one of the other types of predicate. It is clear, too, on the face of it that the man who signifies what something is signifies sometimes a substance, sometimes a quality, sometimes some one of the other types of predicate. For when a man is set before him and he says that what is set there is a man or an animal, he states what it is and signifies a substance- but when a white colour is set before him and he says that what is set there is white or is a colour, he states what it is and signifies a quality. Likewise, also, if a magnitude of a cubit be set before him and he says that what is set there is a cubit or a magnitude, he will be describing what it is and signifying a quantity. Likewise, also, in the other cases- for each of these kinds of predicate, if either it be asserted of itself, or its genus be asserted of it, signifies what something is- if, on the other hand, one kind of predicate is asserted of another kind, it does not signify what something is, but a quantity or a quality or one of the other kinds of predicate. Such, then, and so many, are the subjects on which arguments take place, and the materials with which they start. How we are to acquire them, and by what means we are to become well supplied with them, falls next to be told.
Next in our discussion, we will discuss the different categories of predication that definition, property, genus and accident belong to. There are ten of them: substance, quantity, quality, relation, place, time, position, state, activity and passivity. Definitions, properties, genus and accidents all belong to every one of these categories. Some examples show that this is true. Definitions describe what something is and they can describe substances, qualities or other kinds of predicates in the ten categories. For example, what is humanity and what is whiteness. With any of the ten categories we can ask for the definition of a predicate or what genus that the predicate belongs to. If a predicate belonging to one of the ten categories is said to be true of a predicate in another category, then it does not say what the first predicate is. It says something is true of the thing that it is predicated of. Aristotle is now finished discussing the various categories of predicates.
This discussion has a number of issues. First, the list of ten categories is not defended here. Second, some people believe that this list of ten categories is different from the one in Aristotles Categories. Third, Aristotle does not clearly discuss the place of properties and accidents in the ten categories. Fourth, none of these categories are explained. These issues cannot be resolved here, but they are clearly important elsewhere. For a resolution of the problem, see Aristotle’s Categories.
Next, Aristotle will discuss the range of dialectical propositions and problems in general.