Chapter XV: Introduction

In tracing the fortunes of logic through the period of decadence and the dark ages the effect upon it of a transition from a pagan to a Christian environment need scarcely be taken into consideration. Such marks of degeneration as it shows must be attributed simply to the general decay of thought, which was marked in both pagan and Christian spheres. By its character logic was well adapted to pass from the service of Greek philosophy and science to that of Christian theology: it had been worked out mainly as a method of Greek science, which was especially backward in the fields where induction plays a large part; consequently the Greek logic is not inductive. It is the logic of universals ready-made, and it has nothing to do with their making; it receives universals as authoritative. It was therefore most welcome to Christian thinkers, since it was precisely adapted to “the task of drawing out the implications of dogmatic premises.”[224]

[224] H. W. Blunt, Art. “Logic,” in _Encycl. Brit._, 11th ed.
See also Rashdall, _Universities of Europe in the Middle Ages_
(Oxford, 1895), vol. i, p. 36.

It was not until a very late period that logic appeared in the Latin language in the form of a school text. In fact, with the exception of Varro’s Dialectic in his “Nine Books of the Disciplines,” which has been lost, there were no writings on logic in the Latin down to the fourth century. Instruction in the subject was apparently given in Greek and to but few pupils. In the fourth century, however, Greek was going out of use, and it became necessary, if logic was to be saved in the schools, to have Latin text-books.[225] The need was met by a line of text-writers, of whom Marius Victorinus (c. 350) was the first. The oldest Latin school-book on logic that has survived, however, is that of Martianus Capella. Neither he nor his two successors, Cassiodorus and Isidore, were versed in the subject; they were merely compilers of educational encyclopedias. Such was the perfunctory origin of the Latin text-books on logic.[226]

[225] It was thought that the Latin vocabulary was not well
suited to the expression of the ideas of logic. _Cf._ Martianus
Capella, _De Nuptiis Philologiae et Mercurii_ (ed. Eyssenhardt)
where Dialectica is about to speak: “Ac mox Dialectica, quanquam
parum digne latine loqui posse crederetur, tamen promptiore
fiducia restrictisque quadam obtutus vibratione luminibus etiam
ante verba formidabilis, sic exorsa.”

[226] It is true that the works of Boethius, which were not
school texts, served to revivify the subject, but his influence
was very slight in this respect until long after Isidore’s
time. M. Manitius, _Geschichte der lateinischen Literatur des
Mittelalters_ (München, 1911), pp. 29–32.

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]

[227] 2, 26, 15. _Cf._ Cass. Migne, _P. L._, vol. lxx, col. 1170.

[228] 2, 27, 1. _Cf._ Cass. Migne, _P. L._, vol. lxx, col. 1170.

[229] 2, 28, 22. _Cf._ Cass. Migne, _P. L._, vol. lxx, col. 1173.

[230] The substance of Isidore’s _De Dialectica_ is taken chiefly
from Cassiodorus. A number of passages seem to be based on
Martianus Capella: for example, _Etym._, 2, 31, 1, on Martianus
Capella (Eyssenhardt), 118, 8 ff.; _Etym._, 2, 31, 4–5, on M. C.,
118, 15–25; _Etym._, 2, 31, 7, on M. C., 120, 9 ff.

ANALYSIS

I. Definition of dialectic (chs. 22, 23).
1. Distinction between dialectic and rhetoric.
II. Definition of philosophy (ch. 24).
III. The Isagoges[2] 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).

[231] Isidore’s ignorance of Greek has been inferred from his use
of the forms, _isagogae_ and _perihermeniae_. See p. 36.

EXTRACTS