way: by choosing appropriate but unfamiliar names for characters, objects, and processes. Every name seems foreign yet credible. The science-fiction reader values this kind of invention above subtle differentiations in character. The non-science-fiction reader often finds "the funny names" puzzling at best, off-putting at worst. "Psychohistory" has proved so apt a name that it has been picked up as terminology for an academic discipline, though not, to be sure, the discipline Asimov had in mind. The names of characters are subtly altered, by changing the spelling, or dropping or rearranging letters, to suggest evolution within continuity, and the shifts increase as the series progresses: Hari Seldon leads to Hober Mallow leads to Han Pritcher leads to Bail Channis and eventually to Arkady Darell. Possibly only Heinlein was Asimov's superior in creating future societies, though several other writers have been better with names.
Asimov, however, was the master of the epigraph. Models of imitation, clarity, and dramatization, they offer some preview of his later skill at science popularization. The epigraphs serve as a medium for exposition, which became increasingly burdensome as the series continued a long essay Arkady writes for school in "Search by the Foundation" serves this function (and also convinced Asimov that the series had to end there) but which helped Asimov provide essential back-ground information. They also provide a framework that puts events into context and lends to the structure the verisimilitude of a future perspective.
The final virtue of the Trilogy, and perhaps the most important to its extended popularity, is its exhaustive treatment of an idea. That idea was not psychohistory or even determinism: it was the Foundations.
Each story examined one aspect of the Foundations and their relative positions in the Galaxy and in the events happening around them. In "The Psychohistorians," for instance, the problem for the Foundation is how to persuade the Empire to let the Foundation be set up on Terminus and how to persuade 100,000 Encyclopedists and their families to leave the comfort and security of Trantor for the rigors and uncertainties of the frontier. This problem, of course, is concealed until the conclusion, even until after the resolution. "The Encyclopedists" presents the next problem: how is the Foundation to survive the power of the barbarians that surround Terminus as the Empire slowly begins to lose its control of the periphery? The first solution is to play each group of barbarians against the others; the second, to supply the barbarians with atomic energy within a religious framework centered around Terminus.
In "The Mayors" the problem has become: what will happen to the Foundation when the barbarians are completely equipped with atomic weapons and are restless to use them? The answer: the priests of the scientific religion will not permit an attack on Terminus. In "The Traders" the question has changed to how Foundation hegemony will spread once the religious framework is recognized as a political tool of the Foundation. The answer is: by trade. Economic motivations can succeed where religion fails. Sometimes two problems converge in one story, as in "The Merchant Princes.'' The political and religious structures have rigidified into useless tradition, and the location of the Foundation has been discovered by the Empire. The solutions to those problems are that the Traders seize political power and that war against the Foundation can only succeed in making an attacker poorer.
Each problem solved strengthens the Foundation and its progress toward ultimate reunification of the Galaxy, but each solution contains the seed of a new problem. In "The General," the Foundation faces the problem of its own success, which has made it an attractive prize for the Empire. But it is protected by the essential nature of a decaying Empire a weak Emperor cannot permit strong generals. In "The Mule" and its