One evening, becoming reflective after we'd clucked for a couple of hours over the unbroken human history of warfare, implied and express, I asked the professor whether, from his perspective, he was optimistic or pessimistic about the future of our species.

"Oh," he said immediately. "I'm very pessimistic." He didn't need to explain.

His remark, obviously, was unforgettable. I thought of it again this past week, as Hamas, the militant Palestinian group, began firing rockets into Tel Aviv, and the Israel Defense Force responded with aerial bombs. Dozens of citizens on both sides died, in particular quite a few children, whose role in this long-standing conflict is unclear.

Most of us remember, no doubt, the upsetting opening scene of the film 2001: A Space Odyssey, in which the suddenly enlightened apes switch from shouting at their adversaries to clubbing them to death with old femurs they find lying around. Looking about us today, in a world made ever more visible by ubiquitous and instant communication, it's difficult to determine whether millions of years of evolution, chronicled carefully by sapiens – the intelligent one – have produced anything but ever more sophisticated femurs.

I am sick almost to death of the taunting justification, "Well, they started it!" That sort of yap ought to have been left on the elementary school playground. Any idiot can start a conflict, and it takes very little imagination to respond in kind. The real mensch is the person who can resist being provoked, who seeks instead to mitigate the original provocation and prevent a lethal response.

That isn't easy, and has often proven to be impossible. The United States has always had, for example, a Department of War (euphemized after World War II to the Department of Defense). But when Dr. Benjamin Rush, one of the signers of the Declaration of Independence, called in 1793 for an equivalent Department of Peace, the idea withered on the vine – just as it has about a dozen times since. I suspect we all feel deep down that, given our general lack of imagination and knee-jerk response to perceived threats, the idea really won't work.

The male supremacists of Afghanistan, who, with the same absence of irony with which we call ourselves sapiens, call themselves the Taliban –­ "the Scholars" – are not about to abandon their desire to replace the current deeply corrupt government. The Revolutionary Guards are not about to back away from their commercial monopolies or political influence in Iran. China, Russia, Myanmar, Ukraine, the United States Congress, and many others come to mind. Even Ireland threatens to teeter again. Here in the United States, our divisions and distrust are epidemic. As the Kingston Trio sang some years ago, "The whole world is festering with unhappy souls..."

I begin to suspect my professor friend's pessimism was well-founded. If anyone has any idea what's to be done, short of Kurtz's valedictory "Exterminate all the brutes!" I'd like to hear it. Meanwhile, the Irish singer Tommy Sands' lyric from "There Were Roses" runs often though my mind: ...But centuries of hatred have ears that cannot hear. An eye for an eye was all that filled their minds, And another eye for another eye till everyone is blind. There were roses, roses...And the tears of the people ran together.

You'd think that if we really are the intelligent creatures we've named ourselves, we'd have the discipline to at least stop killing our innocent children in the midst of our lethal squabbles.