Included within this larger work are several major treatises. Every critical thinker would do well to study “Categories,” “On Interpretation” and the first and last parts of “Topics.” Posterior Analytics is interesting while Prior Analytics is highly technical.
Categories is the intro text to Aristotle’s Metaphysics, or so said some essay from Plato.Stanford.Edu said. Good enough for me. It is short and clear. It also gives us the grammar for later Christian theology.
Some things are predicable of a subject but never in a subject. By “being present in a subject” Aristotle means “incapable of existence apart from a subject” (2, 1a).
Substance is that which is neither predicable of a subject nor present in a subject.
- Primary: The individual man or horse. (this-ness)
- Secondary: the species man; the genus animal.
Key point: everything except primary substances is either predicable of a primary substance or present in a primary substance. The proposition “the man is an animal” is necessarily true, but not the reverse. Further, the species is to the genus as the subject is to predicate.
A primary substance has no contrary, for what can be the contrary to an individual man? Yet, while remaining numerically one it can admit contrary qualities.
Chapter 6: What is Quantity?
It is either discrete or continuous. Time, for example, is a continuous quantity.
Chapter 10: Opposites
Things are opposed in four ways:
- Privatives to positives
- Affirmatives to negatives
Chapter 12: Being “prior’
There are four senses in which a thing can be “prior:”
- Numerical sequence
- Order in a list
- Natural priority
Every proposition must contain a subject and a verb.
Contradictories: the opposite denial of an affirmation. The affirmation is of a universal character. The denial is not. One must be true and the other must be false.
Universal: that which is of such a nature that can be predicated of many subjects
Contrary: the positive/negative proposition of a universal character.
Goal: state the moods and nature of the syllogism made from possible premises.
A perfect syllogism: when the last term is contained in the middle premise as a whole, and the middle is either contained in, or excluded from, the first as in or from a whole, the extrames must be related (24a 34).
Major term: the term in which the middle is contained.
All premises in the mode of possibility are convertible to each other (32a 24). “It is not possible” = “it is impossible” = “it is necessary not to belong.”
This is a more readable treatise than the previous one. His thesis is that not all knowledge is demonstrative. Our knowledge of immediate (i.e., not mediate) premises is independent of demonstration (72b). Logical demonstration is an inference from necessary premises.
From there Aristotle moves to some comments on essences.
Essential attribute: it belongs to its subject as an essential element (like a line in a triangle). They “inhere” in the subject. This gets tricky. When Aristotle says “inherence,” does he mean they exist “within” the subject?
With this knowledge Aristotle explores how a middle term in a syllogism, one that is necessary, leads to universal knowledge (75b).
Every syllogism is affected by means of three terms. For example, A inheres in C by means of A’s inhering in B and B’s inhering in C.
More on substance-language. Predicates which signify substance signify that the subject is identical with the predicate or a species of the predicate. For example, if A is a quality of B, then B cannot be a quality of A. You can’t have a quality of a quality.
The Heart of the Matter is the Middle Term
“Quick wit is the faculty of hitting upon the middle term instantaneously” (89b). The middle term in a syllogism can sometimes be seen as the “Cause.”
This is a guidebook on how to refute Hellenic sophists. Very technical.