â€œPessimism,â€ according to John Kenneth Galbraith, â€œis the mark of a superior intellect.â€ Many pessimists would no doubt agree. And yet, if another mark of a serious intellect is attention to facts, then Galbraith is wrong, and so are the pessimists. The facts give us great reason for optimism.

Marian L. Tupy, a scholar at the Cato Institute, has assembled a vast number of those facts at a fascinating new website, humanprogress.org. Its interactive maps and tables allow you to examine for yourself the ways in which the â€œevidence from academic institutions and international organizations shows dramatic improvements in human well-being.â€

Consider, for example, infant mortality: Only half a century ago, more than 100 children of every 1,000 who were born perished within a year. That figure has plunged 80 percent.

Or consider warfare: In the 1500s and 1600s, the worldâ€™s great powers warred against one another more often than not, and almost constantly during certain periods. Over the past several decades great-power conflict has been the exception rather than the norm.

Those changes produce others: â€œAverage global life expectancy at birth,â€ Tupy wrote recently in Reason, â€œhovered around 30 years from the Upper Paleolithic to 1900.â€ In 2010 the global average life expectancy was 67, and it is on the cusp of reaching 68.

The conditions in which people live have improved vastly as well. Until the Industrial Revolution the great majority of humanity scratched out a miserable subsistence from the Earth by farming from sunup to sundown. They had no electricity, no refrigeration, no painkillers, and no means of travel or communication faster than a horse. Now even the developed worldâ€™s poor enjoy amenities â€" central heating, cellphones â€" that the worldâ€™s richest aristocrats could not have dreamed of at one time.

Those in the developing world are not so well off (though 24 percent of the people of Niger, for example, had cellphones by 2010 â€" compared with only 0.02 percent a decade before). And most are far better off today than they were half a century ago. According to the Center for Global Development, more than half the worldâ€™s people live in places where GDP â€œhas increased more than fivefold over 50 years.â€Indiaâ€™s economy has increased tenfold since 1960.Chinaâ€™s has grown 17-fold. And even those in the underdeveloped world are seeing their lot improve: â€œIn sub-Saharan Africa,â€ Tupy writes, from 1990 to 2012 â€œ(daily) caloric intake (per person) increased from 2,180 to 2,380.â€

More gleanings from the Human Progress website? People have more leisure: The typical Dutch citizen works 40 percent fewer hours per year than in 1950. People enjoy better housing: Twenty-three percent fewer people in Bangladesh live in slums now than in 1995. They get more education: Worldwide, the mean number of years of schooling an adult had received in 1980 was 4.7. By 2011 it was 7.6. Womenâ€™s circumstances are improving: Gender wage gaps are shrinking, and the number of women in ministerial-level positions is growing.

Does this mean everything will soon be perfect, and so our work is done? Not even close. Tupy does not mean to suggest the world is all rainbows, butterflies and unicorns. The goal of Human Progress â€œis not to paint a rosy picture of the state of humanity, but a realistic one.â€ To do that, he writes, one should â€œcompare the imperfect present with a much more imperfect past, rather than with an imagined utopia of the future.â€

Indeed. If the horrors of the 20th century hold any one lesson, surely it must be the danger inherent in utopian thinking. As someone or other pointed out, if you truly believe you hold the plans for perfecting human existence, then it is easy to justify savagely repressing anyone who stands in your way. It was the utopians â€" not the skeptics or the ironists â€" who built Russiaâ€™s gulags. It was the utopians who droveChinaâ€™s populace into communes and hence into famine â€" and who covered the Cambodian killing fields with a carpet of bones. As Thomas Adcock wrote, the dirty business of a noble cause never ends.

If grand utopian schemes do not improve humanityâ€™s lot, then what does? According to a June piece in The Economist, one answer is: capitalism. In â€œToward the End of Poverty,â€ the magazine notes that from 1990 to 2010, the number of people in extreme poverty worldwide declined by nearly 1 billion â€" â€œand it was growth, principally, that has eased destitution. … Around two-thirds of poverty reduction within a country comes from growth. Greater equality also helps, contributing the other third.â€

While â€œtargeted policies â€" basic social safety nets and cash-transfer schemesâ€ can alleviate poverty somewhat, the â€œbiggest poverty-reduction measure of all is liberalizing markets to let poor people get richer. That means freeing trade between countries (Africa is still cruelly punished by tariffs) and within them (Chinaâ€™s real great leap forward occurred because it allowed private business to grow).â€

Economic growth contributes to progress in other realms as well â€" e.g., by aiding the ecosphere: â€œRich countries pollute less relative to output,â€ according to the Human Progress website. Environmentalism is a virtue, but it also is largely a luxury of the middle class. Indigenous peoples will stop slaughtering elephants for ivory, for instance, when they can make a better living doing something else.

If we have so many grounds for optimism, then why is there so much pessimism? Evolutionary psychology suggests one explanation, captured well by Laurence J. Peterâ€™s quip that a pessimist is someone who looks both ways before crossing the street. If youâ€™re constantly scanning your environment for threats, then you have a better chance of surviving. You might not stop to smell the roses, but you are more likely to pass on your DNA than the chipper oaf who does â€" completely oblivious to the poisonous snake he is about to step on. Obtuse complacency is a quick path to the grave.

But we do not have to make what President Barack Obama would call a â€œfalse choiceâ€ between obtuse complacency and foul-tempered despair. It is possible to embrace a third alternative: The world remains a dangerous place, full of great suffering that must be addressed â€" yet it has grown far less dangerous and sorrowful than it was not so very long ago. This is good news.