Where do ethical principles come from? James Davis poses some interesting comments on whether and in what way "nature's universal physical laws ... offer guidance toward universal moral laws." See his "Free Will, Ethics, and Natural Law," parts I and II, on the Message Board under Philosophy for Real Life Monday Night Group. For this meeting, please read James' essay and my blog post on "Ways to Say 'Should'" at http://www.bmeacham.com/blog/?p=622.
This group typically reads a short article, often a blog post by Bill Meacham, ahead of time and discusses it at the meeting. We approach philosophy as free human beings engaged in the world. The discussion format is free-form, and it is always quite lively.