J. Budziszewski has good article in this month’s First Things entitled “Natural Law Revealed.” Here’s the pithy conclusion:

Under the influence of the Enlightenment, natural-law thinkers scrubbed, little by little, whatever influence remained from the centuries of faith–whatever benefit they might have gained from the help of revelation. And, as a result, they lost the idea of nature, then the idea of law, and finally the idea of thinking. In the end, they found that they had scoured away the ground on which they were standing.