Enneads III.5: Of Love, or "Eros."
Beauty Is Immortal
They who join to this passion as much of a desire for immortality as our mortal nature admits, seek beauty in the perpetuity of the procreation which renders man imperishable. They determine to procreate and produce beauty according to nature; procreating because their object is perpetuity; and procreating beautifully because they possess affinity with it. In fact, perpetuity does bear affinity to beauty; perpetual nature is beauty itself; and such also are all its derivatives.