[…] at the first attainable period of our knowledge of it [language], whether by actual record or by the inferences of the comparative student, it [language] is in a state of almost endless subdivision; and yet every sound linguist holds, and knows 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- whether of a single one […].
- Whitney (1875), a pag.175-176

The classifications and relations of speech are what they are, without any reference to underlying questions of race; and yet, those questions cannot be kept down and ignored by the linguist: his study is too thoroughly a historical one, it involves too much of the element of race in the later periods, to allow of our leaving that element out of account for the earlier. As one of the leading branches of historical investigation, as claiming to make its contribution to the elucidation of the past, it must offer its results to be criticised by every other concurrent branch.
- Whitney (1875), a pag.276

The linguist looks to see both how many and how close the asserted correspondences [between words] are, and in what part of the vocabulary they are found.
- Whitney (1875), a pag.170