To sum up, then, the doctrine of the two preceding sections: What are we to understand by a _person_, and by _personality_? Unquestionably our conception of person and personality (concrete and abstract) is mainly determined, and very rightly so, by an analysis of what constitutes the actually existing individual of the human species. Whatever our concept be, it must certainly be realized and verified in all human individuals: these, before all other beings, must be included in the denotation of our concept of person. In fact, for the philosopher, guided by the natural light of reason alone, the term can have hardly any other connotation. He will, no doubt, ascribe personality, as the highest mode of being he knows of, to the Supreme Being; but he will here ascribe it only in an analogical and supereminent way; and only from Divine Revelation can he know that this Supreme Being has not a single but a threefold Personality. Again, his consideration of the nature of the human soul as an embodied substance which is nevertheless spiritual and immortal will enable him to affirm the possibility of _purely spiritual_ created beings; and these he will of course conceive as persons. But, conceiving the human soul itself as a constituent principle of the human individual, he will not conceive the soul itself as a person. The philosopher who understands the traditional Aristotelian conceptions of substance, of individual substance (_substantia prima_), of incomplete, complete, and composite substances, of substance considered as _nature_ or principle of action, of substance considered as _hypostasis_, as the actually existing individual being which is the ultimate logical subject of all predications and the ultimate ontological subject of all real determinations: the philosopher who understands these concepts, and who admits them to be validly grounded in experience, and to offer as far as they go a correct interpretation of reality, will have no difficulty in making up his mind about what is requisite to constitute a person.