Natural Law Theory: Just a Weird Catholic Thing?

To preserve space and separate issues, I have made a distinct post on my own question posed to Professor Helen Alvare at the Casey Lecture at the Archdiocese of Denver.

My question, in all its turgidity:

You mentioned natural law. It's become a concern to me that natural law is coming to be seen as just this "Catholic thing." I think Martha Nussbaum was making that argument in a constitutional case. The more I look around, the more I see that people dedicated to Natural Law end up converting to Catholicism, which doesn't help us politically. [And philosophically, I add, since Natural Law theory presumes or predicts adherents among all people and religions -kjj] Could you reassure me that Natural Law debates are taking place outside of the Catholic Church as well?

Professor Alvare briefly passed the question off to seminary professor Sister Prudence Allen, a great thinker in her own right, who reflected on the differences between Protestant or Enlightenment natural law, like Locke and Hobbes, which sees rights coming out of conflict, instead of being based in goodness or in the common good and common things. She concluded her brief response(unworthily summarized here) saying that if you can get in touch with the deepest desires of the heart, you will get a natural law-like answer, which itself ultimately points to God.

Professor Alvare then replied:

"Natural Law has, in the public mind, become synonymous with fideism, something the exact opposite[of what it really is], something only Catholics can know by virtue of faith! So I have tried to stay away from it, and I haven't really tried to think about it completely, but I try to draw a contrast between the world that they are proposing, which is the one in which physical reality is meaningless: the embryo is meaningless, the stem cell is meaningless, the trauma that a surrogate mother goes through is meaningless, that this meaningless phenomenon ought to have no impact on the debate. What is it then? Why is it in the world? Men's and women's bodies, their complimentarity, the institution of marriage arising pre-legally, they tell us nothing? So I more posit that world versus the one we are proposing without calling it Natural Law."

A good answer, especially given the time permitted. I worry that those whom Professor Alvare engages are far too eager to embrace meaninglessness and call it wisdom than consider the burdensome but also liberating alternative of a meaning-full life.