AS the Seventh Aphorism asserted that novelties in language may be and ought to be introduced, when they aid the enunciation of truths, we now declare that they are not admissible in any other case. New terms and new systems of terms are not to be introduced, for example, in virtue of their own neatness or symmetry, or other merits, if there is no occasion for their use. I may mention, as an old example of a superfluous attempt of this kind, an occurrence in the history of Astronomy. In 1628 John Bayer and Julius Schiller devised a _Cœlum Christianum_, in which the common names of the planets, &c., were replaced by those of Adam, Moses, and the Patriarchs. The twelve Signs became the twelve Apostles, and the constellations became sacred places and things. Peireskius, who had to pronounce upon the value of this proposal, praised the piety of the inventors, but did not approve, he said[28\4], the design of perverting and confounding whatever of celestial information from the period of the earliest memory is found in books. [Note 28\4: Gassendi, _Vita Peireskii_, 300.] Nor are slight anomalies in the existing language of science sufficient ground for a change, if they do not seriously interfere with the expression of our knowledge. Thus Linnæus says[29\4] that a fair generic name is not to be exchanged for another though apter one: and[30\4] if we separate an old genus into several, we must try to find names for them among the synonyms which describe the old genus. This maxim excludes the restoration of ancient names long disused, no less than the needless invention of new ones. Linnæus {291} lays down this rule[31\4]; and adds, that the botanists of the sixteenth century well nigh ruined botany by their anxiety to recover the ancient names of plants. In like manner Cuvier[32\4] laments it as a misfortune, that he has had to introduce many new names; and declares earnestly that he has taken great pains to preserve those of his predecessors. [Note 29\4: _Phil. Bot._ 246.] [Note 30\4: _Ib._ 247.] [Note 31\4: _Phil. Bot._ 248.] [Note 32\4: _Règne Anim._ Pref. xvi.]