I've been bashing determinism and fatalism a lot lately, so I thought I'd write about an "ism" I like: optimism. For most of my career as a science journalist, I've been a pessimist, harping on all the goals that scientists will probably never attain. Researchers won't discover a "theory of everything," explain the origin of the cosmos or of life, build fusion generators that produce cheap, clean energy, or warp-drive spaceships that zip us to other galaxies. In The End of Science (Addison Wesley, 1996), I derided the British biologist and Nobel laureate Peter Medawar for declaring, "To deride the hope of progress is the ultimate fatuity, the last word in poverty of spirit and meanness of mind."

Now, perhaps because I'm a father and teacher (and hence, dare I say it, a role model), I've come to agree with Medawar, at least about social (as opposed to scientific) progress. I'm worried about the persistence of war and militarism, global warming and other threats to nature, extreme poverty and social injustice, AIDS and other diseases. I nonetheless believe that pessimism about humanity's future is wrong, both morally and empirically. Morally because pessimism can undermine our efforts to solve our social problems. Empirically because our history shows that these problems are far from insurmountable.

A class I started teaching last fall—an exploration of Plato, Kant, Darwin, Marx and other titans of western civilization—presented me with the opportunity to make these points. Our readings included President John F. Kennedy's inauguration speech in 1961, when he asked his fellow Americans to join him in the quest to end poverty, disease, tyranny and war. I polled my students on whether they thought these four goals were reasonable or just utopian fantasies that politicians invoke in speeches but no one really does or should take seriously. Every single student chose the utopian-fantasy option. So young and so pessimistic!

I spent the rest of the class trying to change their minds by offering reasons why they should be optimistic. As I have noted recently on this blog and in The Chronicle of Higher Education, humanity has taken tremendous strides toward overcoming the scourges identified by Kennedy. Over the past two centuries, average standards of living have surged—first in Europe, cradle of the Scientific and Industrial Revolutions, and then elsewhere—as a result of innovations in agriculture, transportation, communications and other key industries. Since the early 20th century, life spans have more than doubled to a global average approaching 70 years as a result of advances in the delivery and care of infants, improved treatment of water and sewage, better nutrition, vaccines, antibiotics and other medical and public-health measures.

The number of people living under democratic rule worldwide has risen from 12 percent in 1900 to more than 60 percent today. And contrary to the implication of news headlines about civil wars and insurgencies, drone strikes, terrorist attacks and other acts of group violence, our era is quite peaceful by historical standards. Annual war casualties in the past decade have been roughly an order of magnitude smaller than the annual rate in the second half of the 20th century and two orders of magnitude less than the rate in the first half of the century.

And let us not forget that as recently as the late 1980s, humanity faced the threat of a global nuclear holocaust that could destroy not just the U.S. and its archrival, the U.S.S.R., but all life on Earth. Then, incredibly, the Soviet Union dissolved and the Cold War ended peacefully. Since then, the U.S. and Russia have slashed their nuclear arsenals almost in half, and President Barack Obama has kept his pledge to withdraw American troops from Iraq.

Yes, we still face enormous problems globally, and continued progress is by no means guaranteed. We may never entirely eradicate poverty, disease, tyranny and war, as JFK hoped. But given how far we’ve come toward creating a healthier, wealthier, freer and more peaceful world, surely we can go much further, especially if we reject pessimism and work to solve our problems. Journalist and peace activist Norman Cousins liked to say, "We don't know enough to be pessimists." I'd go further than Cousins: We know enough to be optimists.

One more thing: Our extraordinary capacity for envisioning and choosing—creating!—better futures for ourselves represents yet another refutation of the attacks on free will by neuroscientist Sam Harris, biologist Jerry Coyne and other hard-core determinists. History and science alike tell us that we should believe in free will, and a brighter future.

Addendum: To be fair to Harris, he's optimistic about the prospects for ending war. Brian Lehrer of WNYC Radio recently asked Harris, "Do you think, in the context of your thinking about free will, that humans could ever abolish war?" Harris responded: "Yeah, I do. I think our violent tendencies are obviously difficult to rein in. But the reality of war, or the endurance of war, is the result of the fact that we do not have a regime of international law that is really enforceable." You can hear the rest of Harris's response, and responses by other pundits to the question of whether war can end, at http://soundcloud.com/brian-lehrer-show/sets/the-brian-lehrer-show-end-of.

Image courtesy Wikimedia Commons.