Around the year 387,
Saint Augustine wrote this little text on logic, spanning only about 20 pages. According to his own account in
Retractationes, the book was never finished, and he lost his only copy of the manuscript. However, the text we have genuinely seems to be written by him.
In spite of its opening statement, "Dialectic is the science of disputing well" (p. 5/82),
De Dialectica does not contain much that we would now recognize as logic. It's a discussion of a number of topics related to language, most notably ambiguity and etymology.
Truth Values and Dispute
One notable feature of Augustine's discussion of 'dialectics' is that he seems to take
dispute to be more fundamental than
truth values. A meaningful statement has a truth value in virtue of being up for discussion – not the other way around.
In his words:
For either a statement is made in such a way that it is held to be subject to truth or falsity, such as 'every man is walking' or 'every man is not walking' and others of this kind. Or a statement is made in such a way that, although it fully expresses what one has in mind, it cannot be affirmed or denied, as when we command, wish, curse, or the like. For whoever says 'go into the house' or 'oh that he would go into the house' [utinam pergat ad villam] or 'may the gods destroy that man' cannot be thought to lie or to tell the truth, since he did not affirm or deny anything. Such statements do not, therefore, come into question so as to require anyone to dispute them. (p. 6/85)
He consequently adopts the term "statements that require disputation" as a name for what we would call truth-functional statements (p. 6/85).
Eloquence and Proloquence
He later introduces the distinction "expressing" / "asserting" (
eloquendo /
proloquendo) to indicate the difference between the statements that "require questioning and disputing" and those that do not (p. 7/87).
This leads him, in the Chapter XII on "the force of words," to make he following wonderful comment on the relation between logic and rhetoric:
For although disputation need not be inelegant [ineptam] and eloquence need not be deceptive [mendacem], still in the former the passion of learning often – indeed, nearly always – scorns the pleasures of hearing, while the in the latter the more ignorant multitude [imperitior multitudo] think that which is said elegant is said truly. Therefore, when it becomes apparent what is proper to each, it is clear that a disputer who has any concern to make his points appealing will sprinkle them with rhetorical color, and an orator who wishes to convince people of the truth will be strengthened by the sinews and bones, as it were, of dialectic, which are indispensable to the strength of the body but are not allowed to become visible to the eye. (p. 13–14/103)
So logic and rhetoric are inner and outer values – but logic is not inner as in the soul, but inner as in internal organs.
An Observation on Implication
Another interesting feature is that he takes implication to be inherently connected to argumentation:
Whoever says 'if he is walking, he is moving' wishes to prove something, so that when I concede that this combined statement is true he only needs to assert that he is walking and the conclusion that he is moving follows and cannot be denied, or he need only assert that he is not moving and the conclusion that he is not walking must be agreed to. (p. 6/85)
It seems fair to say that Augustine thus sees the meaning of the implication as given by its use in argumentation.
Signification and Writing
In Chapter V, Augustine gives a definition of a sign followed by a slightly strange qualification:
A sign is something which is itself sensed and which indicates to the mind something beyond the sign itself. To speak is to give a sign by means of an articulate utterance. By an articulate utterance I mean one which can be expressed in letters. [Signum is quod et se ipsum sensui et praeter se aliquid animo
ostendit. Loqui est articulata voce signum dare. Articulatum autem dico
quae comprehendi litteris potest.] (p. 7/87)
The intuition behind this comment seems to be the following: If something is said clearly and intelligibly, it can be broken up into its component parts (letters, or phonemes). However, this does seem on he face of it to make verbal understanding dependent on literary understanding.
But maybe this is only because we read too much into the word "letter":
For we misuse the term 'letter' when we call what we see written down a letter, for it is completely silent and is no part of an utterance but appears as the sign of an articulate utterance. In the same way [we misuse the term 'word'] when we call what we see written down a word, for it appears as the sign of a word, that is, not as a word but as the sign of a significant utterance. Therefore, as I said above, every word is a sound [omne verbum sonat]. (p. 7/89)
The theory thus seems to be this: The written word or letter is a sign because it evokes the spoken word or letter to the mind; and the spoken word or letter is a sign because it evokes its referent.
Ambiguity and Obscurity
In Chapter VIII, Augustine introduces a distinction between ambiguity and obscurity. This is not terribly important, but I find his explanation so nice that I wanted to quote it:
When little appears, obscurity is similar to ambiguity, as when someone who is walking on a road comes upon a junction with two, three, or even more forks of the road, but can see none of them on account of the thickness of a fog. Thus he is kept from proceeding by obscurity. […] When the sky clears enough for good visibility, the direction of all the roads is apparent, but which is to be taken is still in doubt, not because of any obscurity but solely because of ambiguity. (p. 14/105)
He goes on to complicate this distinction by distinguishing further between obscurity based on inaccessibility to the mind and to the senses, as in not recognizing a picture of and apple either because one has never seen an apple before, or because it is too dark (p. 14/105).
Problems with Category Membership
In his discussion of ambiguity, Augustine distinguishes between the vagueness of a word like
man and more straightforward cases of homonomy. He calls these two phenomena
univocal and
equivocal meaning, respectively.
This would not in itself be particularly interesting if he didn't get himself into problems by suggesting that a univocal concept is characterized by having "a single definition" (p. 16/111). This of course raises some problems once we start looking for such a definition:
When we speak of a man we speak equally of a boy and of a young man and of an old man, equally of a fool and of a wise man [and a number of further examples]. Among all those expressions there is not one which does not accept the name 'man' in such a way as to be included by the definition of man. For the definition of 'man' is 'a rational, mortal animal' [animal rationale mortale]. Can anyone say that only a youth is rational, mortal animal and not also a boy or an old man, or that only a wise man is and not only a fool? (p. 16–17/111)
So in order to save his definition, Augustine has to assert that a fool is rational, something he seems to sense the problem with:
One may wonder how a boy who is small and stupid [parvo aut stulto], or at least silly [fatuo], or a man who is sleeping or drunk or in a rage, can be rational animals. This can certainly be defended, but it would take too long to do this because we must hasten on to other subjects. (p. 17/111)
This is approximately the same rhetorical strategy he used when defining a sign back in Ch. V:
Whether all these things that have been defined have been correctly defined and whether the words used in definition so far will have to be followed by other definitions, will be shown in the passage in which the discipline of defining is discussed. [This part was never written.] For the present, pay strict attention to the material at hand. (p. 7/87)
Criticism of the Stoic Theory of Etymology
In addition to being an interesting text in its own right, Augustine's tiny book is also one of our prime sources for the Stoic theory of where meaning comes from.
The upshot of this theory is apparently the following: Every word has a meaning which derived metonymically from another word, and ultimately, these chains of metonymies all point back towards an original sound iconicity. Thus, Augustine reports that in order to avoid infinite regress,
… they assert that you must search until you arrive at some similarity of the sound of the word to the thing, as when we say the 'the clang of bronze' [aeris tinnitum], 'the whinnying of horses' [equorum hinnitum], 'the bleating of sheep' [ovium balatum], 'the blare of trumpets' [tubarum clangorem], 'the rattle of chains' [stridorum catenarum]. For you clearly see that these words sound like the things themselves which are signified by these words. But since there are things which do not make sounds, in these touch is the basis for similarity. If the things touch the sense smoothly or roughly, the smoothness or roughness of letters in like manner touches the hearing and thus has produced the names for them. For example, 'lene' [smoothly] itself has a smooth sound. Likewise, who does not by the name itself judge 'asperitas' [roughness] to be rough? It is gentle to the ears when we say 'voluptas' (pleasure); it is harsh when we say 'crux' (cross). This the words are perceived in the way the things themselves affect is. Just as honey itself affects the taste pleasantly, so its name, 'mel,' affects the hearing smoothly. 'Acre' (bitter) is harsh in both ways. Just as the words 'lana' (wool) and 'verpres' (brambles) are heard, so the things themselves are felt. The Stoics believed that these cases where the impression made one the senses by the sounds are, as it were, the cradle of words. From this point they believed that the license for naming had proceeded to the similarity of things themselves to each other. (p. 10/95)
Augustine's main beef with this theory seems that it is too speculative:
Even though it is is a great help to explicate the origin of a word, it is useless to start on a task whose prosecution could go on indefinitely. For who is able to discover why anything is called what it is called? (p. 9/93)
As an example, he gives a couple of hypotheses about the origin of the word
verbum, asking "But what difference does this make to us?" (p. 9/93).
Varieties of Metonymic Shifts
The avenues by which words can jump from meaning to meaning are quite diverse. Twice in the text, Augustine gives a list of relationships that can warrant metonymic slides, once in chapter on "the origin of words" (Ch. VI) and once in the chapter on "equivocation" (Ch. X).
Here's the list from Chapter VI, page 11/97:
Proximity [vicinitas] is a broad notion which can be divided into many aspects:
- from
influence, as in the present instance in which an alliance [foedus] is
caused by the filthiness of the pig [foeditate porci];
- from effects, as puteus [a well] is named, it is believed, from its effect, potatio [drinking];
- from that which contains, as urbs [city] is named from the orbis [circle]
which was by ancient custom plowed around the area […];
- from that which is contained as it is affirmed that by changing a letter horreum [granary] is named after hordeum [barley];
- or by transference [abusionem], as when we say horreum, and yet it is wheat that is preserved here;
- or the whole from the part, as when we call a sword by the name 'mucro' [point], which is the terminating part of the sword;
- or the part from the whole as when capillus [hair] is named from capitis pilus [hair of the head].
Here's the list from Chapter X, page 19/117–119:
I call it transference [translatione]
- when by similarity [similitudine] one name is used of many things, as both the man, renowned for his great eloquence, and his statue can be called 'Tillius.'
- Or when the part is named from the whole, as when his corpus can be said to be Tillius;
- or the whole from the part, as when we call whole houses 'tecta' [roofs].
- Or the species from the genus, for 'verba' is used chiefly of all the wors by which we speak, although the words which we decline by mood and tense are named 'verba' in a special sense.
- Or the genus from the species as 'scholastici' [scholars] were originally and properly those who were still in school, though now all who pursue a literary career [litteris vivunt] use this name.
- Or the effect from the cause, as 'Cicero' is a book of Cicero's.
- Or the cause from the effect, as something is a terror [terror] which causes terror.
- Or what is contained from the container, as those who are in a house are called a household.
- Or vice versa, as a tree is called a 'chestnut.'
- Or if any other manner is discovered in which something is named by a transfer, as it were, from the same source.
You see, I believe, what makes for ambiguity in a word.
The itemization is not in the original. It is interesting that many of these examples are slightly strange or would be analyzed differently (but equally speculatively) today; the relationship of a chestnut tree and a chestnut would, e.g., probably be seen as producer–product relation rather than container–contained.
Word, Thing, Concept, and Word-Thing
One last thing that I want to mention is the rather complicated four-part distinction that Augustine introduces in chapter VI between
verbum,
dicibile,
dicto, and
res.
The last tree can roughly be glossed as concept, word, and thing:
Now that which the mind not the ears perceives from the word and which is held within the mind itself is called a dicibile. When a word is spoken not for its own sake but for the sake of signifying something else, it is called a dictio. The thing itself which is neither a word nor the conception of a word in the mind [verbi in mente conceptio], whether or not it has a word by which it can be signified, is called nothing but a res in the proper sense of the name. (p. 8/89)
The
verbum, however, is a word considered as a thing one can refer to:
Words are signs of things whenever they refer to them, even though those [words] by which we dispute about [things] are [signs] of words. […] When, therefore, a word is uttered for its own sake, that is, so that something is being asked or argued about the word itself, clearly it is the thing which is the subject of disputation and inquiry; but the thing in this case is called a verbum. (p. 8/89)
We thus have here a kind of use/mention distinction, although put in a slightly different vocabulary.
