THERE ARE DECADES WHEN possibility is constrained in a narrow frame. The terrain has been surveyed, boundaries have been laid, and rules have been established. In such an age there is still room for high drama: The decisive round of a boxing match draws the eye despite the fact—or perhaps because—the boxers play an antique game. In such times and climes, victory means mastery of existing modes, not the invention of new ones. But nothing human is everlasting. Always there comes a day when spectators search for better games and settlers seek out fresher pastures. That day of change arrives with much confusion and fanfare. Sons dishonor their fathers. Daughters rise against their mothers. Ancestral ideals are cast aside, and possibility staggers forth from its long captivity, ready to wreak vengeance on mankind.

MIDWAY through his 900 page history of biology, zoologist Ernst Mayr considers the problem posed by Alfred Wallace. Wallace was a contemporary of Charles Darwin who independently developed a theory of speciation by means of natural selection. By the time Wallace came on the scene Darwin had been sitting on his evolutionary theory for two decades. Reading Wallace’s 1858 paper “On the Tendency of Species to Form Varities”  spooked Darwin. He did not want to be scooped. Within a year Darwin had rushed his material into an “abstract which… must necessarily be imperfect” as it only gave “the general conclusions” of his theory, and offered only a “few facts in illustration” to support them. We know this abstract well: it was published as The Origin of Species.

MANY HAVE TRIED to pin Trump to Heritage’s “Project 2025.” The Trump campaign has not only refused to endorse Project 2025—they have refused to endorse any detailed policy plan whatsoever. Trump prefers to keep his options open. One unanticipated benefit of this approach is that Republicans have spent much of the last year engaged in intensive but open debates over policy.  Ambitious politicians, congressional offices, and think tanks have laid out their preferred plans on almost every issue of importance. These plans often differ from each other in striking ways. Absent endorsement from Trump or his campaign, no one quite knows which of these policy packages will eventually be adopted as the Republican standard. The Republicans involved have thus been free to debate the merits and costs of each. Take China policy.

IN 2009 PAUL GRAHAM WROTE A THOUGHTFUL ESSAY titled “Cities and Ambition.” There he proposes that a great city is defined by the sort of ambitions it kindles—or perhaps more accurately, the sort of ambitious it gathers. As Graham puts it: