The general argument against adults having even consensual sex with minors is that they aren't able to judge the consequences (emotion, physical, societal, etc...) for themselves and can be easily manipulated, thus the need to make this illegal.

> I'd say that the "to each their own" argument works really well in many situations.

Agreed. The dividing line is generally around an action affecting someone else. If it does, then there is the possibility that we should make it illegal.

Of course, this can become more nuanced. At the risk of getting (slightly) off topic, Deborah Stone's book Policy Paradox (http://www.amazon.com/Policy-Paradox-Political-Decision-Revi...) has an interesting discussion.

See the book: "Policy Paradox: The Art of Political Decision Making" by Deborah Stone for an exploration of this issue of resource arbitration and politics.

One simple example she uses is how do you divide up birthday cake? Equal pieces? What if come people arrive late to the party after you start cutting the cake and giving out pieces? What if some people are full but others have not had dinner yet? What if some people don't like the pieces with chocolate icing?

While we can be "objective" within a set of established priorities, we can't be objective about designing a set of priorities. Albert Einstein wrote on this in "Science and Religion" about how science can tell you about what is and how it is all connected, but it can't tell you what should be.

One other point Stone she makes is that when people are on the outside of an organization they want transparency of the decision making process -- while then the same exact people move to the inside of an organization they suddenly have many reasons why they want decision should be opaque. "Yes, Minister" has a great comedy episode on that called "Open Government".