Steven Weinberg 2002 Humanist of the Year.

A little more than a year ago we might have been discussing such issues as the attempt by religious zealots to thrust intelligent design into public school curricula, the banning of research on therapeutic cloning, the limitations placed on embryonic stem cell research, and the cultural disagreements over astronomers carrying on their work on such "sacred" mountain peaks as Mt. Hopkins in Arizona and Mauna Kea in Hawaii.

But then the world was shaken by the suicidal terrorist attacks of September 11, 2001, against civilians in the United States. And it has continued to witness terrorism by suicide bombers orchestrated against Israeli civilians. Most commentary on these horrors has very properly focused on the harm that was done and the evil that brought it about. Here I would like to concentrate on a different aspect of the attacks of September 11 in the United States and the random attacks by Palestinians against the Israeli people: the fact that these attacks are suicidal.

Such suicidal attacks contain a strong religious element: a denial of those purely human values that we celebrate as humanism and an expectation of some kind of transcendental paradise. Historically, actual religiously motivated suicide has been rare, I suppose for obvious Darwinian reasons. Religion has from time to time motivated suicidal attacks--for example, the attacks on U.S. ships by kamikaze pilots during World War II, which were bound up in the Shinto religion and emperor worship, and the attacks on Sunni Muslim government officials in the thirteenth century by members of an Ismalite sect of Shiites in what is now Iraq and Iran. But it hasn't been common.

Suicide is merely the most extreme form of something that has historically been quite common: religiously motivated self-destruction, including withdrawal from the world and rejection of its good things in hopes of a heavenly reward. In Roman times the priests of the goddess Cybele ritually castrated themselves with stone knives. In Christianity, Jesus enjoined his followers to leave their mothers and fathers. This started a tradition lasting centuries of monks and nuns withdrawing from the secular world--such as the hermits in the deserts of Egypt who lived nasty lives, wonderfully satirized in Anatole France's book, Thais. And although not as extreme in their self-flagellation, monks and nuns continued to withdraw from family life, from the enjoyment of the good things of the world, sacrificing their lives to their faith. As Keats described the monk in his 1820 poem "The Eve of St. Agnes":

   His was harsh penance on St. Agnes' Eve:
   Another way he went, and soon among
   Rough ashes sat he for his soul's reprieve,
   And all night kept awake, for sinners' sake to grieve.

Dava Sobel put it even more poignantly in her 1999 book Galileo's Daughter, in which we learn how Galileo's two illegitimate daughters became nuns--Suor Maria Celeste and Suor Arcangela--apparently willingly living cloistered lives from their late teens onward, without knowing love, family life, preserving themselves as brides of Christ.

And for what? For what are these nuns and monks, for hundreds and hundreds of years, sacrificing themselves? For a god who, if he existed and welcomed such sacrifices, wouldn't be worthy of our respect.

Such self-sacrificial behavior isn't restricted to the Western religions. The Pall scriptures, written down some years after Gautama Buddha's death, tell how Gautama left home, where he had been the privileged son of the ruling family of Sakya, to seek enlightenment. On the night he left the palace, his wife and his little boy were asleep and he wouldn't say goodbye to them because it would distract him from his search for enlightenment. He was trading their happiness for his spiritual advancement. After his enlightenment, he returned as the Buddha and was welcomed as a hero by everyone in Sakya--except for his abandoned wife who wouldn't greet him. I have always admired her for that.

It may seem odd for a theoretical physicist like me to complain about religion leading people to withdraw from the world, because the work we physicists do is extremely esoteric. In its way it sounds, perhaps, like the modern equivalent of medieval scholastics, worrying about the trinity or the other fine points of Christian doctrine. Our work is often incomprehensible to most people (sometimes even to us) and it certainly isn't pursued for any practical purpose but only for its own sake. I have indeed occasionally felt somewhat monkish, and I keep a television set on my desk just to remind me while I'm working that there's a world out there.

But there are differences between the lives lived by scientists, even theoretical physicists, and the lives of monks and nuns. We aren't required to abandon our families, and we are in search of real knowledge, not a self-induced narcosis. Although our work isn't aimed directly at a practical end, it is aimed at discovering the laws of nature and the fundamental principles that govern everything. That, I suppose, was what the medieval monks and nuns were also aiming at. But our work as scientists grapples with something real, something with substance. There are such things as electrons and quarks and supernovas and galaxies. And we are learning about them in a way based not on myth, prophets, and dogma but on data we obtain from observation and theory devised to account for this data--always acknowledging that, in the end, observation of nature has the last word. Part of my own motivation as a scientist is that I hope, by helping to understand the workings of the world, I may do a bit to free humanity from the burden of superstition that demands needless sacrifices--from the self-castration of the priests of Cybele to the suicidal terrorism of today.

It's not enough for us scientists or anyone else to withdraw from the world and just do our work. We have to defend the world. We have to defend the world of science and reason and tolerance and democracy from the religious zealots and others who would destroy it. We can't relax into a kind of relativism that accepts that we will go our way and religious zealots will go theirs, because their way aims at the destruction of ours.

In the 1930s the British author Rebecca West became terrified by what she foresaw as the oncoming war with Nazis and fascists, and she tried to fight the pacifist attitudes that she found in her own country. In her great 1941 work Black Lamb and Grey Falcon: A Journey Through Yugoslavia, West draws an analogy between the pacifism of her time in the face of the Nazis and the pacifism of the Serbs at a key moment of their history: the battle of Kossovo in 1389, in which the Serbs under Tsar Lazar were defeated by the Turks, condemning Serbia to 500 years of subjugation. This story is told in a poem quoted by West, known to all Serbs, that describes the circumstances of the peculiar Serbian passivity in the face of the Turkish attack. As translated by West's friend, the poem reads:

   There flies a grey bird, a falcon
   From Jerusalem the holy,
   And in his beak he bears a swallow....

   He comes to the Tsar at Kossovo,
   He lays the book on the Tsar's knees.
   This book without like told the Tsar:
   "Tsar Lazar, of honorable stock,
   Of what kind will you have your kingdom?
   Do you want a heavenly kingdom?
   Do you want an earthly kingdom?
   If you want an earthly kingdom,
   Saddle your horses, tighten your horses' girths,
   Gird on your swords,
   Then put an end to the Turkish attacks!
   And drive out every Turkish soldier.
   But if you want a heavenly kingdom
   Build you a church on Kossovo;
   Build it not with a floor of marble
   But lay down silk and scarlet on the ground,
   Give the Eucharist and battle orders to your soldiers,
   For all your soldiers shall be destroyed,
   And you, prince, you shall be destroyed with them.

The poem goes on to tell how the tsar chose a heavenly kingdom and built the church and gave the Eucharist and battle orders to his soldiers. The Turks attacked, and the poem continues:

   Then the Turks overwhelmed Lazar,
   And the Tsar Lazar was destroyed,
   And his army was destroyed with him.
   Of seven and seventy thousand soldiers.

   All was holy, all was honorable,
   And the goodness of God was fulfilled.

Humanity must choose an earthly kingdom because there isn't any heavenly kingdom. We have to make our realm a place of reason and democracy and freedom from religious tyranny and defend it--as the United States has been doing in Afghanistan and as Israel has been doing since its inception. We have to defend our realm and humanist values from all enemies who would destroy them.

Steven Weinberg is the Josey Regental Chair of Science and a member of both the physics and astronomy departments of the University of Texas at Austin. He has authored several books and numerous articles and is the recipient of many awards, including the 1979 Nobel Prize in physics, the National Medal of Science, the Heinemann Prize in mathematical physics, the Madison Medal of Princeton University, the Oppenheimer Prize, and the 2002 Humanist of the Year Award of the American Humanist Association. This essay is adapted from remarks delivered in acceptance of the latter honor.