Heraclitus, who taught that all things are in a state of flux, and to that of Protagoras in ethics who maintained that man is the measure of all things. Plato doubtless carried his doctrine to an unwarranted extreme, but that there is much truth in it will hardly be doubted. Neither the mute man nor even the mute child is without ideas. The ability to mould language so that it will fit thought closely is the highest human achievement, but it is not essential to thought. The thought-processes of deaf-mutes are to some extent beyond our grasp, but not wholly out of the range of the constructive imagination. It is well to note, furthermore, that our word logic is the direct descendant of Logos. Whatever technical or philosophical definition we may give to logic, there is no doubt that speech and rational thought were closely associated in the minds of the Greeks as the history of the term proves. In their philosophical systems dialectic, discussion, question and answer were so intimately connected and interwoven that they were unable to think of them as separated. People who live in an age of books can only realize with a mental effort conditions when they were non-existent or rare. The poet-philosopher Euripides, who flourished about the middle of the fifth century b.c., is said to have been the first man to collect a library. In the nature of the case it must have consisted at most of only a score or two of manuscripts. Besides, he lived in Athens, the center of culture in the ancient world; elsewhere there were strictly speaking no books at all. Our dictionaries designate what they believe to be correct usage. At any rate, they do much to establish it by setting up a standard to which all educated persons endeavor to conform. In this way a language becomes stereotyped to such an extent that it changes very slowly. But dictionaries in the popular sense are of comparatively recent date. The Greeks always felt justified in using any word or phrase they found in Homer, just as we do with respect to biblical or Shakesperean phraseology. But these authors did not get their vocabulary from books. Later writers, notably Plato among the Greeks and Cicero among the Romans, endowed with the power of genius, may be said to have created a language; it was subsequently imitated with more or less success by all who strove after elegance of diction. But it is doubtful whether they formed a single word in the sense in which a modern scientist may be said to do so. Neither does a man who makes a machine make the materials that enter into it. The influence of these two writers is still vibrant in all philosophical and ethical discussion. The same may be said of Kant, another of the world's great thinkers and one of its original geniuses, since he was not much interested in ancient philosophy and preferred to grapple with the problems he set out to solve without the intervention of predecessors. While we can not tell how thought-processes are carried on without words, that they are so carried on does not admit of doubt.
