RICHARD OF ST VICTOR (+1173)
Where there is supreme and perfect charity, there must necessarily be a plurality of persons. For love cannot exist without a beloved, nor can it be perfect unless it is shared. If a person loves himself alone, that love is not charity but self-regard. Perfect charity requires not only one who loves and one who is loved, but also one who is loved by both in common. Thus, where there is fullness of divine charity, there must be a Trinity of persons, not by necessity of nature alone, but by the perfection of love itself.