It belongs to every man to be a person, inasmuch as everything subsisting in human nature is a person.
 Thomas Aquinas, Summa Theologica (1274). copy citation

add
Author Thomas Aquinas
Source Summa Theologica
Topic human nature
Date 1274
Language English
Reference
Note Translated by Fathers of the English Dominican Province
Weblink http://www.gutenberg.org/cache/epub/19950/pg19950-images.html

Context

“Secondly it may be taken that in Christ a proper personality, caused by the principles of the human nature, is due to the human nature; and in this way Christ as Man is not a person, since the human nature does not exist of itself apart from the Divine Nature, and yet the notion of person requires this. Reply Obj. 1: It belongs to every man to be a person, inasmuch as everything subsisting in human nature is a person. Now this is proper to the Man Christ that the Person subsisting in His human nature is not caused by the principles of the human nature, but is eternal. Hence in one way He is a person, as Man; and in another way He is not, as stated above.” source