On the knowledge of good and evil, the dynamic boundaries of what constitutes "right", and what would lead even the Pope to kill

The minority of American voices still hostile to open support for Ukraine in its fight to repel Russia's invasion tend to fall into two camps. One is aligned, either openly or sympathetically with the myth of an imperial Russia. The other claims it is merely against war and in favor of de-escalating the conflict by whatever means are available.

■ Both camps should acquaint themselves with the advice of the ancient philosopher Lucius Seneca: "There is but one thing that brings the soul to perfection -- the unalterable knowledge of good and evil."

■ It really isn't hard to distinguish which side has enthusiastically embraced evil in this war; Russian forces have made unspeakable and persistent violence against civilians a strategic centerpiece of their conduct of the war. Civilian targets in Kyiv, far from the front lines, are being attacked purely to create terror. Mass graves are being uncovered as Ukrainian towns are being liberated. Even the word "children" isn't enough to command mercy.

■ So, for those who are sympathetic to the aggressors, the "knowledge of good and evil" should be plain. But for those who claim merely to be against conflict (or perhaps against Western engagement in the conflict), it really shouldn't be much harder to tell the difference.

■ Finland's prime minister -- a person who herself must contemplate the real risk of Russian aggression -- put it plainly: "The way out of the conflict? The way out of the conflict is for Russia to leave Ukraine. That's the way out of this conflict."

■ Even great principles have boundaries. "Thou shall not kill" may be a rule nearly asymptotic to being right all of the time, but one imagines that even the Pope would kill a homicidal maniac with his bare hands if that were the only way to spare the lives of a room full of innocent children. Likewise, avoiding war may be the right thing to do most of the time -- but not "at all costs", if those costs include vast human suffering and the snuffing out of many thousands of lives.

■ Knowing good and evil isn't a matter of mechanically observing perfect rules. It is a consequence of learning the boundaries of good and bad, and realizing that those boundaries are not always static. To be anti-violence all of the time, without exceptions, is to intrinsically invite more violence by those willing to commit it. Some tools, like deterrence, are best used by those who are reluctant, but not unwilling, to put them to use.