[…] communication is the leading determinative force throughout. This it is for which and by which we make our first acquisitions; this leads us, when circumstances change, to lay our old acquisitions aside and make new; this determines the unity of a language, and puts a restraint upon its dialectic variation; this is, both consciously and unconsciously, recognized by every individual as the regulator: we speak so as to be intelligible to others; we hear and learn that we may understand them; we do not speak simply as we ourselves choose, letting others understand us if they can and will.
- Whitney (1875), a pag.286-287

[…] the great and wonderful powers of the human soul would never move in this particular direction [language] but for the added push given by the desire of communication; when this leads the way, all the rest follows. Our recognition of the determining force of this element is far from implying that communication is the sole end, or the highest end, of speech.
- Whitney (1875), a pag.284-285

[…] the main determining element in the whole history of production of speech; it is the desire of communication. This turns the instinctive into the intentional. As itself becomes more distinct and conscious, it lifts expression of all kinds above its natural basis, and makes of it an instrumentality, capable, as such, of indefinite extension and improvement.
- Whitney (1875), a pag.283-284

As the direct object of language is communication, the possibility of communication makes the unity of a language.
- Whitney (1875), a pag.157

It is true that a certain degree of power of communication, sufficient for the infinitely restricted needs of their gregarious intercourse, is exhibited also by some of the lower animals.
- Whitney (1875), a pag.2

Language [...] signifies rather certain instrumentalities whereby men consciously and with intention represent their thought, to the end, chiefly, of making it known to other men: it is expression for the sake of communication.
- Whitney (1875), a pag.1

The community’s share in the work [language-making] is dependent on and conditioned by the simple fact that language is not an individual possession, but a social. It exists […] not only partly, but primarily, for the purpose of communication; its other uses come after and in the train of this. To the great mass of its speakers, it exists consciously for communication alone; this is the use that exhibits and commends itself to every mind.
- Whitney (1875), a pag.149

The necessity of communication is the restraint upon the alterative processes, and communication is the means whereby any alteration actually made is adopted by all. Whatever, then, makes communication most lively and penetrating, through all regions and all ranks, will tend to preserve the unity of speech most strictly through the whole community. On the other hand, all that dulls the forces of communication, and lets a people break up into tribes, or into widely-sundered castes or classes, tends to increase the discordance of the forms comprehended together in the general language.
- Whitney (1875), a pag.157

Where the impulse to communication is wanting, no speech comes into being.
- Whitney (1875), a pag.284