individual species. But still there is an analogy between the faculties of Vital Principle and geometrical figures; for as in vital properties, so in geometrical figures, the antecedent is ever present potentially in the sequences, and as the triangle is in the square, so the nutritive is in the sentient faculty. Thus, the inquiry must be conducted with reference to individuals, in order to learn what is the Vital Principle of each, as of a plant, a man, or a brute; and wherefore beings are thus ranged in a series.

Without the nutritive function there can be no sensibility, but in plants the nutritive exists without the sentient; so again without the Touch there can be no other sense, while Touch can exist alone, for many animals have neither sight nor hearing, and are altogether without smell. Among sentient creatures some have and some have not locomotion, and, finally, to a few calculation and judgment have been imparted; and to such among mortal beings as are so endowed all other faculties have been imparted likewise. But to such as possess some one only of the faculties, calculation has not been allotted, as some of them have not even imagination, while others live by it alone; it would be foreign to our present inquiry to enter upon the speculative intellect.

It is, then, clear that the definition which comes closest to each one of those faculties is also the fittest for the elucidation of Vital Principle.

PRELUDE TO CHAPTER IV.

THE opening paragraphs of this chapter are both obscure and apparently contradictory; for while it is suggested that it might be well, in order to comprehend faculties or functions, first to study the energies or organs from which they emanate, yet the inquiry reverts to nutrition as a fact; without reference, that is, either to vital processes or to food. We may assume that Aristotle was unacquainted with the rudimentary forms and development of the corporeal organs, and yet, judging from this exor dium, he seems to have perceived that every part must advance from a nascent state to its perfected condition; and thus he has suggested the teaching of developmental anatomy. As the inquiry proceeds, we are reminded of the obscurity or inaccuracy of language, in portraying the impressions upon and the functions, so to say, of the sentient organseven now the external object is, with us, in common parlance, a sensible object; sensation, besides its own

sense, implies casual feelings from within; sight signifies both faculty and function; and nourishment is food as well as digestion. It is somewhat, perhaps, objectionable that Aristotle should have bound up, so to say, the generative with the nutritive function, seeing how they differ both in the periods of development and duration; they are equally necessary, no doubt, to nature's design, but still they are neither contemporaneous nor identical With respect to spontaneous generation here alluded to Aristotle' admitted its possibility, and for obvious reasons, in the case of eels; and, although he denied that all mullets (τοὺς κεστρεῖς φύεσθαι πάντας) are so reproduced, yet he believed that some of the species spring forth (púerai) from the mud and sand on the sea-shore; and thus it is evident, he continues, that some creatures, not being derived from others, may be the product of spontaneous generation. This opinion upon reproduction prevailed for many ages, and even yet, perhaps, notwithstanding the advancement of science, it may not be altogether discredited.

1 Hist. Ani. VI. 14. 14. 15. 3.

CHAPTER IV.

It is necessary, in order well to study those faculties, that we should comprehend what each of them individually is, and then, in like manner, carry our inquiry into their consequences and other conditions. But if it behove us to say what each of them is, as what is the cogitative, sentient, or appetitive faculty, it should previously be settled what that is which thinks and that which feels; for energies and acts are, abstractedly considered, pre-existent to their functions. Granting, however, that it is so, and that we ought, before the faculties or functions, to have considered their opposites, it might be fitting here also, and for the same reason, first to define the opposites of the functions-define, that is, food before nutrition; the object before perception; and the intelligible before thought.

Thus we must first speak upon nutrition and generation, for the nutritive faculty is innate in other beings besides animals; it is the primal and most universal influence of the Vital Principle, and through it life is manifested in all beings. Its functions are to generate and to employ nourishment; for the most

natural of the functions in beings which are perfect, that is, which are neither dwarfed nor spontaneously generated, is to produce another such as itself, an animal an animal, and a plant a plant, in order that they may partake, to the extent which has been allotted to them, of the Everlasting and the Divine. All creatures yearn after this, and, for the sake of it, they do all that they do naturally; but since such beings cannot, in uninterrupted continuity, partake of the Everlasting and the Divine, because no perishable being can abidingly continue as one and the same; yet each can partake thereof in its own allotted portion, be it larger or smaller, and still continue, if not the same, like the same, and one, if not in number, as species.

The Vital Principle is the cause and the origin of a living body. Now, cause and origin have several significations; for the Vital Principle is equally a cause, according to any one of the three defined modes of causation as that whence motion proceeds; as that for which motion is produced; and cause, again, as the essence of living bodies. It is evident that it is a cause as an essence, since the essence is in all things the cause of their being what they are; and as life is the mode of being in living beings, so Vital Principle is the cause and the origin of all such. It is the realizing principle, besides, the cause that is of something which exists in potentiality becoming a