On Second Thought: Let's get down to cases, senators

Argument is a way for people with differing perspectives on an issue, abortion, for example, to test and reshape each other's ideas and, sometimes, even reason out a new idea together. Unfortunately, not much reasoning together happens when everybody insists on the kind of high minded principles that inspire Facebook memes and protest signs, such as Life Begins at Conception versus My Body, My Choice.

Arguments on the order of--Abortion is always wrong-- based on grand principles — Because life begins at conception — don't win converts, Worse, that kind of talk guarantees everybody is going to...