3. When the genus animal is mentioned the substance of man is declared. For with reference to man the genus is animal; but since it has a wide application, the species, terrenum, is added and now what belongs to the air or water is excluded. And a difference is added, as, for example, bipes, which is given on account of the animals that go on several feet. Likewise rationale, because of the animals which lack reason; and mortale, because man is not an angel.
4. Afterwards, when the common qualities had been set aside, the property was added at the end, for it is the characteristic of man alone to laugh. In this way the complete definition to indicate man was reached. Aristotle and Tully held that the full definition of this science consisted of genus and differences.
5. Later certain authorities, expressing their position more fully, in their teaching divided perfect substantial definition into five divisions, as if into five organic parts. And the first of these deals with genus, the second with species, the third with difference, the fourth with proper quality, the fifth with accident.
Chapter 26. On the categories of Aristotle.
1. Next follow the categories of Aristotle, which in Latin are called praedicamenta, within which all discourse is embraced throughout its various meanings.
5. There are ten sorts of categories, namely, substantia, quantitas, qualitas, relatio, situs, locus, tempus, habitus, agere, pati.
15. This work of Aristotle ought to be read with attention, since, as has been observed, whatever man speaks is included within the ten categories. It will help also to the understanding of the books that are devoted either to rhetoric or to logic.[233]
Chapter 27. On Interpretation (de Perihermeniis).
1. There follows next the book On Interpretation, which is extremely subtle and guarded in its various formulas and repetitions, of which it is said: “Aristotle when he wrote the Perihermeniae dipped his pen in intellect.”
Chapter 28. On syllogisms.