I may also, in reference to this same passage in Mr. Owen's appeal in behalf of his terminology, repeat what I have said under Aphorism X.: that the persons who may most properly propose new scientific terms, are those who have much new knowledge to communicate: so that the vehicle is commended to general reception by the value of what it contains. It is only to eminent discoverers and profound philosophers that the authority is conceded of introducing a new system of terms; just as it is only the highest authority in the state which has the power of putting a new coinage into circulation. The long series of investigations of which the results are contained in Mr. Owen's table of synonyms, and the philosophical spirit of his generalizations, entitles him to a most respectful hearing when he appeals to the Professors and Demonstrators of Human Anatomy for an unbiassed consideration of the advantages of the terms proposed by him, as likely to remedy the conflicting and unsettled synonymy which has hitherto pervaded the subject. There is another remark which is suggested by the works on Comparative Anatomy, which I am now considering. I have said in various places that Technical {355} Terms are a necessary condition of the progress of a science. But we may say much more than this: and the remark is so important, that it deserves to be stated as one of our Aphorisms, as follows: APHORISM XXV. _In an advanced Science, the history of the Language of the Science is the history of the Science itself._ I HAVE already stated in previous Aphorisms (VIII. and XI.) that Terms must be constructed so as to be fitted to enunciate general propositions, and that Terms which imply theoretical views are admissible for this purpose. And hence it happens that the history of Terms in any science which has gone through several speculative stages, is really the history of the generalizations and theories which have had currency among the cultivators of the science. This appears in Comparative Anatomy from what we have been saying. The recent progress of that science is involved in the rise and currency of the Terms which have been used by the anatomists whose synonyms Mr. Owen has to discuss; and the reasons for selecting among these, or inventing others, include those truths and generalizations which are the important recent steps of the science. The terms which are given by Mr. Owen in his table to denote the bones of the head are good terms, _if_ they _are_ good terms, because their adoption and use is the only complete way of expressing the truths of homology: namely, of that Special Homology, according to which all vertebrate skeletons are referred to the human skeleton as their type, and have their parts designated accordingly.