Hitherto we have examined only the stable, solid parts of speech. There remain such as are purely transitive, translating a movement of thought, expressive of relation. Before we study these under their linguistic form, it is indispensable to take up the standpoint of pure psychology, and to know in the first place what is the nature of a relation. This can the less be avoided inasmuch as the question has scarcely been treated of, save by logicians, or after their fashion, and many very complete treatises of psychology do not bestow on it a single word.[64]
“A relation,” says Herbert Spencer, “is a state of consciousness which unites two other states of consciousness.” Although a relation is not always a link in the rigorous sense, this definition has the great advantage of presenting it as a reality, as a state existing by itself, not a zero, a naught of consciousness. It possesses intrinsic characters: (1) It is indecomposable. There are in consciousness greater and less states; the greater (e. g., a perception) are composite, hence accessible to analysis; they occupy an appreciable and measurable time. The lesser (relation) are naturally beyond analysis; rapid as lightning, they appear to be outside time. (2) It is dependent. Remove the two terms with which it is intercalated, and the relation vanishes; but it must be noted that the terms themselves presuppose relations; for, according to Spencer’s just remark, “There are neither states of consciousness without relations, nor relations without states of consciousness.” In fact: to feel or think a relation, is to feel or think a change.
But this psychical state may be studied otherwise than by internal observation, and the subsequent interpretation. It lends itself to an objective study, because it is incarnated in certain words. When I say, red and green, red or green, there are in either case, not two, but three states of consciousness; the sole difference is in the intermediate state which corresponds with an inclusion or an exclusion. So, too, all our prepositions and conjunctions (for, by, if, but, because) envelop a mental state, however attenuated. The study of languages teaches us that the expression of relations is produced in two ways, forming, as it were, two chronological layers.
The most ancient is that of the cases or declensions: a highly complex mechanism, varying in marked degree with the idioms, and consisting in appositions, suffixes, or modifications of the principal theme.
But these relations have only acquired their proper linguistic organ, specialised for this function, by means of prepositions and conjunctions. They are wanting in many languages; gesture being then substituted for them. The principal parts of the discourse are solitary, juxtaposed without links after the manner of the phrases used by children. Others, somewhat less poor, have only two conjunctions: and, but. In short, the terms on which devolved the expression of relations are of late formation, as it were, organs de luxe. In the analytical languages, prepositions and conjunctions are nouns or pronouns diverted from their primitive acceptation, which have acquired a value expressive of transition, condition, subordination, co-ordination, and the rest. The psychological notion common to the greater number, if not to all, is that of a movement. “All relations expressed by prepositions can be referred to repose, and to movement in space and time, i. e., to those with which the locative, accusative (movement of approximation) and ablative (movement of departure) correspond in declension.”[65] It may be admitted that this consciousness of movement, of change, which is no more, fundamentally, than the sense of different directions of thought, belongs less to the category of clear notions than to that of subconscious states, of tendencies, of actions, which explains why the terms of relation are wholly wanting, or rare, and only conquered their autonomy at a late period.
With these, the progressive work of differentiation is accomplished. Discourse has now its materials and its cement; it is capable of complex phrases wherein all is referred and subordinated to a principal state, contrary to those ruder essays which could only attain to simple phrases, denuded of connective apparatus.
We have rapidly sketched this labor of organogenesis, by which language has passed from the amorphous state to the progressive constitution of specialised terms and grammatical functions: an evolution wholly comparable with that which, in living bodies, starts from the fecundated ovule, to attain by division of labor among the higher species to a fixed adjustment of organs and functions. “Languages are natural organisms, which, without being independent of human volition, are born, grow, age, and die, according to determined laws.” (Schleicher.) They are in a state of continuous renovation, of acquisition, and of loss. In civilised languages, this incessant metamorphosis is partially checked by enforced instruction, by tradition, and respect for the great literary works. In savage idioms where these coercive measures are lacking, the transformation at times occurs with such rapidity that they become unrecognisable at the end of a few generations.
Spoken language, as a psycho-physiological mechanism, is regulated in its evolution by physiological and psychological laws.
Among the former (with which we are not concerned), the principal is the law of phonetic alteration, consisting in the displacement of an articulation in a determined direction. It is dependent on the vocal organ; thus, after the Germanic invasion, the Latin which this people spoke fell again under the power of physiological influences which modified it profoundly.