"Person"

"PERSON signifies what is most perfect in all nature─that is, a subsistent individual of a rational nature. Hence, since everything that is perfect must be attributed to God, forasmuch as His essence contains every perfection, this name "person" is fittingly applied to God; not, however, as it is applied to creatures, but in a more excellent way; as other names also, which, while giving them to creatures, we attribute to God..." 

~St. Thomas Aquinas: Summa Theologiae I, Q. 29, A. 3.

"IT is a very significant fact that the idea of human personality and also the practical recognition of the dignity of human personality developed only during those centuries in which the dogmas of the Trinity and of the Incarnation were teaching Christendom the truths of divine personality."

~Jacques Maritain: Freedom in the Modern World.