The reader of Isidore’s account of logic is struck by the enthusiasm displayed. Speaking of Aristotle’s Categories he says: “This work of Aristotle’s should be read attentively, since, just as is stated therein, all that a man says is included in the ten categories.”[227] Further on he quotes the saying that “Aristotle dipped his pen in intellect when he wrote the Perihermeniae.”[228] Again, a study of Apuleius “will introduce the reader advantageously with God’s help to great paths of understanding.”[229] All of these passages, however, come word for word from Cassiodorus. Isidore’s enthusiasm as well as his bibliography seems to lack genuineness.[230]
ANALYSIS
| I. | Definition of dialectic (chs. 22, 23). | |
| 1. | Distinction between dialectic and rhetoric. | |
| II. | Definition of philosophy (ch. 24). | |
| III. | The Isagoges[231] of Porphyry (ch. 25). | |
| 1. | The five predicables: genus, species, differentia, proprium, accidens. | |
| IV. | The Categories of Aristotle (ch. 26). | |
| V. | Aristotle’s De perihermeniis[231] (ch. 27). | |
| 1. | Thought as expressed in language. | |
| VI. | The syllogisms (ch. 28). | |
| 1. | Categorical syllogisms. | |
| 2. | Hypothetical syllogisms. | |
| VII. | Definition (ch. 29). | |
| The fifteen kinds of definition. | ||
| VIII. | Arguments (topica) (ch. 30). | |
| The twenty-two loci of arguments. | ||
| IX. | Opposites (ch. 31). | |
EXTRACTS
Book II, Chapter 22. On dialectic.
1. Dialectic is the discipline elaborated with a view of ascertaining the causes of things. In itself it is the sub-division of philosophy that is called logical, i.e., rational, capable of defining, enquiring and expressing precisely. For it teaches in the several kinds of questions how the true and false are separated by discussion.
2. The first philosophers used dialectic in their discourses, but they did not reduce it to the practical form of an art. After them Aristotle systematized the subject-matter of this branch of learning, and called it dialectic, because there is discussion of words (dictis) in it; for λεκτὸν means dictio. And dialectic follows after the discipline of rhetoric because they have many things in common.
Chapter 23. On the difference between the dialectical and the rhetorical art.
1. Varro, in the nine books of the Disciplinae, distinguished dialectic and rhetoric by the following simile: “Dialectic and rhetoric are as in man’s hand the closed fist and the open palm, the former drawing words together, the latter scattering them.”
2. If dialectic is keener in expressing things precisely, rhetoric is more eloquent in persuading to the belief it desires. The former seldom appears in the schools, the latter goes without a break [from the schools] to the law-court. The former gets few students, the latter often whole peoples.