A common theme to theories of karma is its principle of causality
Comparative Religion - Reincarnation and Christianity
The Middle Ages was a period of division. Each people, each province, each city, each family then tended strongly to become more individual. Today an opposite movement makes itself felt; peoples seem to march toward unity. Intellectual links unite the most distant parts of the earth, and men cannot remain strangers to one another for a single day, or ignorant of what is happening in no matter what corner of the universe. Consequently you notice today less difference between Europeans and their descendants of the New World, despite the Ocean that divides them, than between certain cities of the XIIIth century that were separated only by a river.
St. Thomas Aquinas on Penance | Called to Communion
Enlightenment, by increasing in the South, made the inhabitants of this part of the territory see that slavery is harmful to the master, and this same enlightenment shows them, more clearly than they had seen until then, the near impossibility of destroying it. A singular contrast results. Slavery becomes established more and more in the laws, as its usefulness is more disputed; and while its principle is gradually abolished in the North, in the South more and more rigorous consequences are drawn from this very principle.