Source: Scientific American
Quantum physicists have discovered that quantum mechanics enlarges our capacity to reason in unexpected ways. The notorious Prisoner's Dilemma, in which the rational choice is the wrong choice, can be eliminated by quantum entanglement. A more recent (and still unproved) claim is that a quantum system of voting could avoid the inconsistencies of ordinary voting.
- Quantum mechanics may be a better model for human behavior than classical logic, which fails to predict the human impulse to cooperate and act altruistically. Instead of trying to force our thinking into a rational framework, we are better off expanding the framework.
Throughout the 20th century scientists and mathematicians have had to accept that some things will always remain beyond the grasp of reason. In the 1930s Kurt Gödel famously showed that even in the rational universe of mathematics, for every paradox that deep thinking slaps down, new ones pop up. Economists and political theorists found similar limitations to rational rules for organizing society, and historians of science punctured the belief that scientific disputes are resolved purely by facts. The ultimate limits on reason come from quantum physics, which says that some things just happen and you can never know why.
Yet events have taken a strange turn in the past decade. The very theory of quantum physics that seemed to box in human knowledge also proves to liberate us. It expands our knowledge not just of the physical world but also of ourselves. By enriching the rules of rational thought, it gets us out of dead ends where reason leads us. Taken in the broader framework quantum physics provides, human behavior may not be as irrational as the evening news makes it seem.
The Weight of Reason
Few lived and breathed the Enlightenment dream more than the Marquis de Condorcet, one of the leading mathematicians of the late 18th century. Emboldened by the success of Newtonian physics, a few simple rules that explained the fall of apples and the orbits of planets, he sought to create a science of society to match. Reason, he thought, could make the world a better place. He and other Enlightenment thinkers campaigned for a progressive political agenda: the abolition of slavery, equal rights for women, universal public education. A friend of Thomas Jefferson, Benjamin Franklin and Thomas Paine, Condorcet became an early leader of the French Revolution. “The moment will come when the sun will shine only on a planet of free men, knowing only reason as their master … learning how to recognize and smother beneath the weight of reason the first signs of superstition and tyranny, should they ever dare to reappear,” he wrote in 1794.
Then came the fall. The revolution took its dark turn. Condorcet was arrested, died in prison the next day and was buried in a communal grave that was later lost. The Enlightenment gave way to Romanticism. For many leading thinkers, the excesses of the revolution discredited the entire progressive agenda.
As if to heighten the tragedy, Condorcet had come to question the Enlightenment idea of the will of the people. He showed that democratic voting systems lead to paradoxes: people's choices can add up in mutually contradictory and unresolvable ways. Mathematician and political essayist Piergiorgio Odifreddi of the University of Turin in Italy gives an example: In the 1976 U.S. presidential election, Gerald Ford secured the Republican nomination after a close race with Ronald Reagan, and Jimmy Carter beat Ford in the general election, but polls suggested Reagan would have beaten Carter (as indeed he did in 1980). The electorate's preferences were intransitive: preferring Carter to Ford and Ford to Reagan did not mean preferring Carter to Reagan. Carter won only because the primaries came first. “Who was elected is determined only by the order in which you do the two elections, not by the electorate,” Odifreddi says. In committees and legislatures, presiding officers can exploit this order dependence, or noncommutativity, to steer a vote their way.