All these theories must be regarded as at tempts to conjecture how speech might con ceivably have arisen instead of as anything even remotely approaching a scientific demon stration of how speech actually did arise. Against the third theory it may be urged that at best it would account for the origin of but very few words. Furthermore it has been shown that of even this relatively small num ber of words, some have attained an onomato poetic character in comparatively recent times, having arisen by changes of movement from words that formerly had quite different sounds, and hence could not be used to substantiate this theory.
In so far as these theories attempt to assign a method of origin to individual words, they are open to the objection that, while we cannot say positively what type or types of thought were employed during primitive, incipient stages of human or pre-human speech, still in all like lihood in these earlier stages (and this seems to hold true of animals also) man had occasion to express only masses of ideas, whole situa tions as yet unanalyzed into detailed ideas such as are expressed by most modern words. A difficulty of the last theory lies in the relatively small number of emotional cries found in a single individual, unless we include the mean ingless cries of children mentioned above, with the consequent objections. The last theory also assumes the existence of speech sounds before thought, which, as was stated above, is as un tenable as the converse assumption..
In contrast with these five theories a more scientific attempt to explain the arbitrary con nection between speech movements and mean ing regards the former, like other gestures, as worn-down remnants of movements that were previously useful (life serving). F. N. Scott (in 'Publications of the Modern Language As sociation of America') has called attention to a variety of such movements of the speech or gans, for example, panting, gasping, grunting, sneezing, coughing, choking, etc. The closing of the glottis necessarily precedes all great muscular efforts of the body. The cessation of such effort is followed by its opening. The necessity of breathing during the strain neces sitates gasping. Many such movements occur in typical situations and in accordance with the normal working of the mental processes would soon become closely associated with them.
Movements of the speech organs productive of sound waves occur also in connection with other movements tnat are life serving. Pant ing, for example, follows upon all vigorous exercise. The sounds thus produced, through association with the movements which produce them and further with the movements which the latter accompany, become also associated with, and hence significant of, the general situation tinder which they arise. In the cases men
tioned the connection between the two groups of concomitant movements is purely physical. There are, however, other groupings, the con nection between which lies in the nervous sys tem. Such secondarily produced movements (whether of the vocal organs or other muscles) are explained by psychologists as due to the ((overflow') of exceptionally intense feeling into other nervous channels than those within which they would naturally he supposed to be con fined. Instances of such complexes of move ment occur in animals. This view provides no final explanation, however, because it at once suggests the question why and how the nervous connection between the two movements arose, i.e., why the overflow took originally the pre cise channel which it did.
On the other hand there are sound-produc ing vocal movements which may be instinctive in origin and which are also useful in that they contribute to the survival of the individual and hence of the race. The various calls of animals are of this kind, signifying, as they do, "dan ger!'"food," etc. Pre-humans doubtless pos sessed such calls. Assuming that these move ments represented in their earlier stages unan alyzed general situations, it is easy to see how (as mental powers developed in complexity and the consequent analysis of the general situa tions brought specific elements into clearer con sciousness) the specific dominating elements rather than the general complex came to be symbolized by the vocal movements, thus giving origin to expressions more akin in meaning to the majority of existing words.
In general it may be said that the methods of modern science (as applied both in psychol ogy and in linguistic study) constrain the stu dent of the genesis of speech to confine himself in his search for positive evidence to such lin guistic processes as occur in the experience of people now living. This is the only kind of first-hand evidence which can be fully studied by direct examination and which admits of even approximately exact scientific control. Thus the evolutionary processes which are at present taking place form the only safe criteria from which one may draw inferences as to the con ditions that prevailed in earlier times. Prob ably we shall never be able to reconstruct such primitive conditions in detail; we will be lim ited to the possession of certain general truths concerning their nature. In all study of this subject furthermore one must be continually guided by our best contemporary understanding of the mental processes.