The true cause of vital phenomena manifestly depends on these two conditions--the presence of the specific vital unit, and the necessary environing plasma, or nutrient matter, for its primary development. Without the presence of both of these conditions, or conditioning incidences, there can be no life-manifestation anywhere. And we do not see that anything is gained, even in the matter of scientific nomenclature, by merely substituting "molecular force" for "vital force," in the explication of vital phenomena. Even granting that molecular changes do take place during the development of the vital units in their necessary plasmic environment; it by no means follows that these changes are not dependent on the vital principle _as it acts_, rather than on the molecules _as they act_,[34] The higher force should always subordinate the lower in all metamorphic, as well as other processes, of nature. It is the vital principle that differentiates matter--the aggregate of molecules--not matter differentiating the vital principle. No "molécules organiques" can ever differentiate an ape-unit into a man-unit, any more than Professor Tyndall can fetch a Plato out of mere sky-mist. Once an ape-unit, always an ape-unit; once a man-unit, eternally a man-unit. Let the vitalists stick to this proposition--this eternally fixed _unit_ as "_une idée dans l'entendement de Dieu," _ (to use a better French expression than English)--and they can fight the materialists off their own ground anywhere. The one sublime verity of the universe is that "life exists," and that it has existed from all eternity _as possible_ in the Divine mind, and in the Divine mind alone. If materialistic science is disposed to butt its head against this impregnable proposition, it can do so. The proposition will stand, whatever may happen to the inconsiderate head.