This was in a recent Wall Street Journal article on social conservatism:
St. Thomas Aquinas taught that "we do not offend God except by doing something contrary to our own good." If Thomas is right, then rather than claim that a debased practice offends God, politicians can—and, I would add, should—explain to the public what aspect of some immoral behavior is contrary to our own good, especially the common good—and why a just and decent society shouldn't accept it.
This is of a piece with the doctrine that Reason and Faith are not in conflict, and if they appear to be, we have misunderstood something. (It used to be that we had more confidence in our interpretation of revelation than in the findings of science. Actually, that was good reason; science, until the development of scientific method, was not reliable. Those were the days when Astrology and Alchemy were considered good science, and illusionists posed as scientists. Today we have enough experience with the results of applying real scientific method -- that is, framing falsifiable hypotheses and testing them by experiment, and yes, I know that's a reductionism that ignores a number of important implications -- we have enough experience with the results of scientific method to have confidence that scientific truth is important, and if science conflicts with revelation then we have probably misinterpreted revelation.
Read the whole thing here.