Hunter Baker, author of The End of Secularism, writes at First Things’ First Thoughts blog:
I think it is fair to say that in [the libertarian] view, the reason we choose to live together in political association rather than as hermits in the woods is so that we can enjoy the benefits of mutual defense and commerce. Thus, all the government we really need is a military to protect against external threats, police to protect against internal ones, and maybe courts to enforce contracts between individuals.
Social conservatives, in contrast, line up more or less with Aristotle, who insisted that political life is about more than just mutual defense and commerce. Instead, political associations exist to enable us to develop a civic friendship whereby we will discover moral excellence as a community.