Wherever he finds an existing individual being of any species, a being which, even if it is really composite, is nevertheless really one, such a being he will pronounce to be a “subsisting individual being”. He may not be able, in the inorganic world or among the lower forms of life, to distinguish for certain what is the real individual from what may be perhaps only an accidental, if natural, colony or group of real individuals. As a test he will always seek for the manifestation of an internal directive principle whereby all the vital functions of the organized mass of matter in question are co-ordinated in such a manner as to make for the preservation, growth and development of the whole throughout a definite life cycle from birth to death. This formative and directive principle is evidence of an individual unity of nature and subsistence; and such evidence is abundantly present in “individuals” of all the higher species in botany and zoology. The “individual subsisting being” will therefore be a “complete individual substance or nature, existing and acting in every way distinct from and incommunicable to any other being, so that it exists and acts _sui juris_, autonomously”. If such an individual nature is not merely corporeal but organic or animate, not merely animate but sentient, and not merely sentient but _rational_ or _intelligent_, _i.e._ constituted at least in part by a _spiritual substantial principle_ whereby the individual is _intelligent_ and _free_, then that individual is a person. Every individual of the human species is such. And all that is essential to his complete individual human nature enters into and constitutes his person in the concrete. Not merely, therefore, his intellect and will; not merely his soul considered as “mind,” _i.e._ as the basis and principle of his whole conscious and subconscious psychic life; or also as the principle of his merely organic life; or also as the actualizing principle of his corporeal nature; but no less also the corporeal principle itself of his composite being, the body itself with all its parts and members and organs: all these without exception belong equally to the human person; all of them without exception go to constitute the _Ego_.(304) This, which is the Aristotelian and scholastic view of the human person, is in perfect accord with the common-sense view of the matter as evidenced by the ordinary usages of language. We speak intelligibly no less than correctly when we say that a man’s body is part of his person as well as his soul or mind. And we make a no less accurate, intelligible, and necessary distinction, when we distinguish between all that which _constitutes_ the human person and that _whereby we know_ ourselves and other human individuals to be persons. Yet this distinction is not kept clearly in mind by many modern philosophers, who, approaching the study of personality exclusively from the side of what the individual consciousness testifies as to the unity