Neither Creator nor a creature ever,
Son,” he began, “was destitute of love
Natural or spiritual; and thou knowest it.

The natural was ever without error;
But err the other may by evil object,
Or by too much, or by too little vigour.

While in the first it well directed is,
And in the second moderates itself,
It cannot be the cause of sinful pleasure;

But when to ill it turns, and, with more care
Or lesser than it ought, runs after good,
‘Gainst the Creator works his own creation.

Hence thou mayst comprehend that love must be
The seed within yourselves of every virtue,
And every act that merits punishment.
Purgatorio XVII