“To give them as much credit as possible, words possess only sufficient efficacy to remind us in order that we may seek things, but not to exhibit the things so that we may know them. He teaches me something, moreover, who presents to my eyes or to any other bodily sense or even to my mind itself those things which I wish to know. By means of words, therefore, we learn only words or rather the sound and vibration of words. For if those things which are not signs cannot be words, even though I have heard a word, I do not know that it is a word until I know what it signifies. So when things are known the cognition of the words is also accomplished. For we do not learn the words which we know, nor can we say that we learn those which we do not know unless their signification has been perceived; and this happens not by means of hearing words which are pronounced, but by means of a cognition of the things which are signified. For it is the truest reasoning and most correctly said that when words are uttered we either know already what they signify or we do not know. If we know, then we remember rather than learn, but if we do not know, then we do not even remember, though perhaps we are prompted to ask.” – Augustine, De Magistro
After reading half of Gordon Clark's "Ancient Philosophy," I feel a little more capable of understanding and relating the context and import of Augustine's arguments in De Magistro than I felt last year when I picked up this ~50 page pamphlet and expected to be done with it in one night (!) In the above quote, Augustine is positing a thoroughly Christian exposition to an ancient problem, viz.
"Sextus argued that a thing becomes a sign only when it is related to the thing signified, and the problem is precisely to discover what it is that is signified. If the thing signified were already known, the sign would of course be useless, but, if the thing signified is not known, neither do we know that this present thing is a sign at all, let alone a sign of that one definite thing." - Gordon Clark, Ancient Philosophy
"When signs are used, the pupil either knows the thing signified or he does not. If he does not, the sign teaches him nothing... But if the pupil already knows the thing signified, the pronunciation of the word leads him to associate the sign with the thing signified that he already knows; and he learns that the word is a sign only through knowing the thing. Otherwise it might be merely be a noise without significance. The thing, therefore, must be known first; the sign is learned later." – Gordon Clark, Thales to Dewey
Showing that one cannot learn the association between a sign and a thing by first learning the sign is simple: suppose that the contrary were true. If one wished to explain to a friend that which the word “tree” signifies, for example, how would one go about teaching his friend? Why, by pointing at a tree, of course. But if the friend doesn’t know the sign, then perhaps he will mistake his friend’s finger as the signification of “tree.” All signs which signify sensible objects suffer similar possible misunderstandings. Explaining a sign with an incorporeal referent is just as difficult, for the only method of explanation would presuppose knowledge of signs with incorporeal referents. Then again, by what other means can two people know that which is being signified so as to relate it to a communicable sign? How is the thing signified known first?
Only by divine revelation (the grounds) is justification of knowledge possible, and so too only by divine illumination (the means) can men understand and assent to truth. Man “is taught not through my words but by means of the things themselves which God reveals within the soul” (De Magistro). Socrates, for example, did not teach Meno's servant how to double the area of a square; he did not need to: “Communication is of course possible only by means of words or some other signs; but the words, instead of teaching anything new, rather stir up our memories of things we had previously understood” (Thales to Dewey). While man’s words can serve as the occasion by which one is reminded of what he has forgotten or the clarification of what he innately knows, Christ alone is the epistemological Logos that “gives light to every man…” (John 1:9). God is our “only Master,” and Christ, God’s “everlasting wisdom,” is He whom “every rational soul does indeed consult” (De Magistro).