"In ethics, common sense regards the direct, intentional killing of an innocent human being as gravely immoral, and the A-T philosopher agrees with common sense. But it is not that its commonsense status shows that such killing is immoral; rather, the fact that it is gravely immoral accounts for our intuitive sense that it is. And so forth. Nature has formed our feelings and intuitions so that they provide us with a rough and ready practical guide to what is true and good. But their intuitive status is a consequence of their being true and good, not the ground of their being true and good." -- Edward Feser.
A-T = Aristotelian-Thomistic