Fourfold categories development in Aristotle.

Question

According to J.L. Ackrill, a key to understand his fourfold classifications of things we must understand two different notions:

1. "Being in something as a subject"
2. "Being said of something as a subject"

The first one, according to him, set up the difference between "substantial" and "non-substantial" and the second one between "species and general" from "individuals".

So, from there, we might have:

1. Species and genera in the category of substances.
2. Species and genera in the category of non-substances.
3. Individuals in the category of substances.
4. Individuals in the category of non-substances.

I have some questions:

1. What counts as a subject?
2. How is being "in something" equivalent to "substance"?
3. How is being "said of something" equivalent to "species and genera"?
4. What is the relationship between "Substances" and "Species and genera"?

Extra: Some source with a more simple way to get into this idea?

Thanks.

Answer 1

Long comment

Species and genera are universals : they are predicated of individuals : "Plato is bald".

This corresponds to the modern relation of "belongs to" : an individula belongs to a class or set.

We can also "predicate" an universal of another universal : "man is mortal".

This corresponds to the modern relation of "to be included in" : the class of men is a subclass of the class of mortal beings.

See Aristotle's account of substance :

primary substances are individual objects, and they can be contrasted with everything else—secondary substances and all other predicables—because they are not predicable of or attributable to anything else.

The marks of primary substance are:

Being objects of predication but not being themselves predicable of anything else .

If substance did not exist it would be impossible for things in any of the other categories to exist. There could be no instances of properties if there were no substances to possess them.

Answer 2

I'm going to paraphrase J.L. Ackrill translation of Aristotle's Categories and de Interpretatione

"Said of something" can be interpreted as a generalization from an individual. For example, we could say of Socrates that he is a human. In this sense, we are moving from an individual to a species or genera; from a particular to a universal. Thus, we have individuals and universals.

Then, we have things that are "in a subject" in the sense that they cannot exist separately from the things that possess them and also things that can exist independently of everything else.

By combining the previous concepts we have:

1. Species and genera in the category of substance: This would be generalizations from things that can exist independently and are not in any other substance. For example Men, since it is a genera of Socrates, which could be a substance.

2. Species and genera in the categories other than substance: This would be generalizations of things that are normally part of a substance and cannot exist independently of it. For example the color white, which, in the case of an individual white it cannot exist without its individual subject on which it is predicated.

3. Individuals in the category of substance: Individual substances are the primary substances because they are not “In something” nor are they “said of something”, thus they must be the ultimate substance. Everything else must be predicated on them.

4. Individuals in categories other than substance: Individuals that are in substances in the sense that they are part of some other substance and cannot exist independently of them.