and thus persisted in acquiring secret knowledge that the Party had no direct access to. This was a familiar problem that came with two familiar solutions: the employment of Mercurian strangers and the repeated extermination of the bearers of autonomous knowledge. The second solution (embraced after the mid- 1930s, when strangeness became suspect) proved both cheap and effective because the detective work demanded by Stalin required little special training beyond the mistaken conviction that unmasking more enemies was the best way not to become one. Few professional groups within Soviet society had as high a mortality rate or as little understanding of the nature of their work as the secret police. In 1940, the doomed architect of the Great Terror, N. I. Ezhov, had said: “I purged 14,000 Chekists. But my great guilt lies in the fact that I purged so few of them.” In 1952, the doomed architect of the Jewish “affair,” M. D. Riumin, wrote: “I only admit that during the investigation I did not use extreme measures , but after my mistake was pointed out to me, I corrected it.” 144 Another professional group that undermined the official orthodoxy as a matter of course were the nuclear physicists, whose success in building the bomb seemed to depend on their rejection of Engels’s “dialectics of nature.” Because the building of the bomb was of paramount importance, the official orthodoxy (including the newly mandated mistrust of ethnic Jews) had to be partially waived for the duration of the project. What made such suspension of belief possible was the fact that the group in question was extremely small and the affected portion of the canon relatively marginal. What made it dangerous in the long run was the implicit recognition by the Party that its authority was political and not transcendental. Few professional groups within Soviet society had as high a status or as little need for Marxism-Leninism as the atomic scientists. Finally, there were the physicians. Under normal circumstances, their expertise did not obviously challenge the Party’s monopoly on truth, but when Stalin entered his seventies and began to lose his vigor, it became clear that the life of the “great leader and teacher”—and thus the fate of world socialism—was in the hands of professionals whose claim to vital knowledge could not be checked or verified—except by other professionals. The Soviet unity of knowledge and virtue had always been tenuous: in one purge after another, experts had been unmasked as wreckers, engineers as saboteurs, spy catchers as spies, and priests as black magicians. Doctors, who fought death for a living, had been featured as “poisoners” at the Bukharin trial of 1938 and in numerous rumors about the untimely deaths of various Soviet leaders. They were never targeted as a class, however—until Stalin confronted limits to his immortality and Jews were identified as key agents of contagion. The first court physicians to