[…] all the known Indo-European languages are descended from a single dialect, which must have been spoken at some time in the past by a single limited community, by the spread and emigration of which- not, certainly, without incorporating also bodies of other races than that to which itself belonged by origin- it has reached its present wide distribution […].
- Whitney (1875), a pag.191-192

[…] at the first attainable period of our knowledge of it [language], whether by actual record or by the inferences of the comparative student, it is in a state of almost endless subdivision; and yet every sound linguist holds that he has the most satisfactory reasons for holding, that this apparent confusion is a result of the extension and divarication of a certain limited number of primitive dialects […].
- Whitney (1875), a pag.175-176

[…] if this process of tradition, by teaching and learning, were to cease in any tongue upon earth, that tongue would at once become extinct. But this is only one side of the life of language. If it were all, then each spoken dialect would remain the same from age to age. In virtue of it each does, in fact, remain nearly the same; this is what maintains the prevailing identity of speech so long as the identity of the speaking community is maintained […].
- Whitney (1875), a pag.32

[…] individuals of every degree of gift are found using, each according to his power, the same identical dialect […] Not seldom, far greater race-differences are met with among the speakers of one language, or of one body of resembling languages, than between those who use dialects wholly unlike one another.
- Whitney (1875), a pag.3-4

[…] no language on earth exists in a state of absolute accordance through the whole community that speaks it; it is a group, even if a very limited one, of related dialects.
- Whitney (1875), a pag.228

[…] the distribution of human dialects is as irreconcilable with that of natural capacity and bent as with that of physical form among human beings.
- Whitney (1875), a pag.9

[…] the learned find what they want most conveniently in the learned languages. They gain in addition the practical advantage that all the inheritors and continuers of a common civilization thus possess something like a common dialect, in which to denominate those conceptions in which they have a joint interest closer than that which they have with the mass of their countrymen.
- Whitney (1875), a pag.119

[…] the meaning of the terms ‘language' and 'dialect’, in their relation to one another. They are only two names for the same thing, as looked at from different points of view. Any body of expressions used by a community, however limited and humble, for the purposes of communication and as the instrument of thought, is a language; no one would think of crediting its speakers with the gift of dialect but not of language. On the other hand, there is no tongue in the world to which we should not with perfect freedom and perfect propriety apply the name of dialect, when considering it as one of a body of related forms of speech.
- Whitney (1875), a pag.177-178

[…] the uncultivated have current in their dialect a host of inaccuracies, offences against the correctness of speech- as ungrammatical forms, mispronunciations, blunders of application, slang words, vulgarities […].
- Whitney (1875), a pag.155

[…] there are the differences of age: the nursery, in particular, has its dialect, offensive to the ears of old bachelors; and older children have their language at least characterized by limited vocabulary.
- Whitney (1875), a pag.156

The science of language has democratized our view […] it has taught us that one man’s speech is just as much a language as another man’s; that even the most cultivated tongue that exists is only the dialect of a certain class in a certain locality […] English and Dutch and German and Swedish and so on, are the dialects of Germanic speech; and the same, along with French and Irish and Bohemian, and the rest, are the dialects of the wider family […] This is the scientific use of the terms; in the looseness of popular parlance, an attempt is made at the distinction of degrees of dignity and importance by means of the same words, as when the literary language of a community is alone allowed the name of language, and the rest are styled dialects. For ordinary purposes the usage is convenient enough; but it has no acceptableness on other grounds; it forms no part of linguistic science.
- Whitney (1875), a pag.178

The science of language is what its name implies, a study of all human speech, of every existing and recorded dialect, without rejection of any, for obscurity, for remoteness, for lowness of development.
- Whitney (1875), a pag.191

There is also a state of things intermediate between the two extremes of barbarism and all-pervading culture: namely, where there is culture which reaches only a particular class, a minority, of the community, its conserving influence being mainly limited to that class. This alone possesses the records of the language, and, using them as models, propagates its speech nearly unaltered, while the language of the mass goes on changing unchecked. There comes thus to be a separation of the originally unitary speech into two parts: a learned dialect, which is the old common language preserved, and a popular dialect, which is its altered descendant; and the latter, perhaps, finally crowds the former out of existence, and becomes in its turn, the cultivated speech of a new order of things.
- Whitney (1875), a pag.158-159

To the scores of tribes and nations of discordant speech in India; the Sanskrit has long been the sacred and literary dialect, and its literature the fountain of higher thought and knowledge […].
- Whitney (1875), a pag.117

We know that the separation and isolation of the different parts of a once unitary community must necessarily bring about a separation of its language into different dialects; and we know that this process may go on repeating itself, over and over again; and that, at the end, those dialects which parted latest will (apart from special altering forces), though unlike, be least unlike and most like one another, while those which parted earliest will be least like and most unlike one another […].
- Whitney (1875), a pag.173