[Virgil]: “The soul, which is created quick to love,
responds to everything that pleases, just
as soon as beauty wakens it to act.
Your apprehension draws an image
from a real object and expands upon
that object until soul has turned toward it;
and if, so turned, the soul tends steadfastly,
then that propensity is love – it’s nature
that joins the soul in you, anew, through beauty.
Then, just as flames ascend because the form
of fire was fashioned to fly upward, toward
the stuff of its own sphere, where it lasts longest,
so does the soul, when seized, move into longing,
a motion of the spirit, never resting
till the beloved thing has made it joyous.
Now you can plainly see how deeply hidden
truth is from scrutinists who would insist
that every love is, in itself, praiseworthy;
and they are led to error by the matter
of love, because it may seem – always – good;
but not each seal is fine, although the wax is.” (Purg. XVIII, 19-39)
Virgil explains how man comes to love objects. Not surprisingly, it works like a fantasy, wherein a person's senses first discover something aesthetically pleasing. Then the soul takes over and “draws an image from a real object”; in other words it takes that object of desire, perfects it, and puts it up on a pedestal to admire and lust after. If the soul lusts after that object “steadfastly” or repeatedly, it becomes love, though it may be perverted love if the object isn't worthy of being loved. This is why some people are wrong in asserting that “every love is, in itself, praiseworthy.”