In a commentary today, First Things editor and Creighton theologian R.R. Reno parses the justifications for killing an abortion doctor like George Tiller, and finds that alleged murderer Scott Roeder came up short–though barely. Reno says that “The blanket condemnation [by Catholics bishops and others] of ‘violence’ seems unhelpfully expansive” and so he wants to explain that the reasons Tiller’s killer was wrong “are not as simple as they seem.”

Reno says that under Christian thinking, such an action would have to satisfy three conditions: It would target the guilty, not the innocent; it would have to be necessary (principally to protect others); and it would have to be an act of self-defense that does not “violate the principle of legitimate authority” by being premeditated and calculated violence, as Tiller’s killing was. Reno says the suspect got only two out of three:

The emphasis on “unlawful use of violence,” the evocation of “vigilantism,” and the description of Tiller’s killer as a “vigilante killer” are all exactly right. We are all sinners, but it is painfully obvious that Dr. George Tiller acted in wanton disregard for the sanctity of life. Killing him did not violate the principle of innocence. Moreover, he gave no evidence of stopping. As a result, perhaps something like the principle of necessity can be satisfied. But it is certainly obvious that his killer was acting as the law unto himself. He arrogated to himself the roles of jury, judge, and executioner. He violated the principle of legitimate authority.

That strikes me as far too close to justification, as others would argue that unjust laws shouldn’t stop us. With their redesigned site, the First Things blog now allows comments, and the first commenter on Reno’s thread pressed him to go further, asking how Reno’s argument would apply to Bonhoeffer or the Nazi resistance. Good question.