"Consequently, any activity that is potentially harmful to others and requires certain demonstrated competence for its safe performance, is subject to regulation that is, it is theoretically desirable that we regulate it. ... In fact, I dare say that parenting is a paradigm of such activities since the potential for harm is great (both in the extent of harm any one person can suffer and in the number of people potentially harmed) and the need for competence is so evident. Consequently, there is good reason to believe that parents should be licensed."
"Licensing Parents", Philosophy and Public Affairs, Winter 1980