When in 1988 Mikhail Gorbachev declared competition the essence of socialism, Francis Fukuyama said: "We've reached the end of history." In 1989, the year of the fall of the Berlin Wall, Fukuyama published, in the National Interest quarterly, "The End of History?" Widely read, fiercely debated and frequently misunderstood, it had remarkable fecundity as the catalyst of serious thought about political choices after the death of communism.

Since then, Gorbachev has appeared in a Pizza Hut ad, and Fukuyama's thesis -- call it melancholy triumphalism -- has seemed confirmed. It is that the exhaustion of ideological alternatives to bourgeois liberalism -- rights-based, pluralist, market societies -- presages the unification of mankind in agreement on the fundamental aims of life.

History, he argues, is directional, progressive and approaching its destination. However, the agreed-upon aims of life are banal -- constitutionalism and consumerism, a world made safe by tamed governments and publics sedated by material satiation.

This tranquillity will be purchased by the trivialization of man, who will be reduced to the material appetites of his animal nature. Yeats, in perhaps this century's most quoted couplet, said:

The best lack all conviction, while the worst

Are full of passionate intensity.

However, throughout history the best, too, have usually had passionate intensity, without which bravery and other forms of nobility are unlikely.

Ten years on, Fukuyama, now with George Mason University, has published, again in the National Interest, "Second Thoughts." He affirms the premise of his earlier argument. However, he retracts, for ominous reasons, his conclusion about the human project approaching finality.

His premise is that two motors drive history. One is economic, meaning applied science -- from steam power to computer chips -- which increasingly punishes societies that do not maximize, through markets, the dispersal of decision-making. History's second motor is what Hegel called the individual's "struggle for recognition," meaning equal dignity as a moral agent, which liberal democracies affirm with a panoply of rights.

In the 1990s U.S. foreign policy looks like Fukuyama's premises transmuted into policy through what he calls "three interlocking propositions constituting a `democratic syllogism.' " The propositions are:

First, liberal democracies rarely fight one another.

Second, the correlation between a certain level of economic development and democracy strongly suggests that economic development is the most efficacious promoter of democracy. Above "a level of $6,000 per capita GDP in 1992 parity purchasing power," says Fukuyama, "there is not a single historical instance of a democratic country reverting to authoritarianism. Spain, Portugal, Greece, Taiwan and South Korea all made their transitions to democracy at or near this magical figure."

Third, the best way to promote growth is globalization -- integrating nations into international trade and capital markets.

Fukuyama says the "evolutionary logic" of history, imparted by "the integrating forces of economic modernization," is not refuted by the persistence of premodern nationalisms and ethnic conflicts in Rwanda, Somalia and the Balkans, or the cultural resistance of Islamic theocracies. In 1999, even more clearly than in 1989, only democracy legitimizes a regime, and supposed alternatives to market arrangements, principally the "Asian development model" exemplified by Japan's state-directed development, seem discredited.

And yet, says Fukuyama, his "end of history" thesis was wrong. It assumed that human nature is a known constant. But to assume that, there would have to be an "end of science," and particularly of biology, the source of the new neuropharmacology, and perhaps soon much else.

Just with the widespread use of Ritalin and Prozac, "a major revolution in the control of social behavior has been launched in the past decade without fanfare or significant debate." And that major revolution is minor compared with the potential alterations that may be made possible by manipulations of the structure of DNA.

Our understandings of political justice and general principles of morality reflect our understanding of human nature. Hence all bets about the destination of directional history are off when that nature becomes malleable -- something not given by God or evolutionary inheritance but by human artifice. This artifice can produce new motors of history, with unknowable potentials for good and evil.

In a sense, Fukuyama's thesis -- that human history is no longer driven by passionate differences -- is not vulnerable to what science does: It will not really be refuted if human nature is abolished and post-human history begins.

Meanwhile, his thesis is largely unscathed by a decade's events: Liberal market democracy still is the only alternative for peoples wishing to participate in modernity, as all peoples seem to wish to do as soon as their societies become porous to today's information technologies.

So far, so good. The trouble is, a decade, even one as eventful as that since 1989, is but a blink in the human story.