Thomas Aquinas,
Summa Theologiae — Question 19 - OF THE GIFT OF FEAR…
“ Now whoever does a thing through love, does it of himself so to speak, because it is by his own inclination that he is moved to act: so that it is contrary to the very notion of servility that one should act from love. Consequently servile fear as such is contrary to charity: so that if servility were essential to fear, servile fear would be evil simply, even as adultery is evil simply, because that which makes it contrary to charity belongs to its very species. ”
