From Robert Conquest’s “Stalin, Breaker of Nations” (mentioned in Mockingbird’s interview with Whit Stillman).

One of [Stalin’s] outstanding characteristics was, in many respects, a profound mediocrity melded with a superhuman will-power. It is as though he had a very ordinary brain, but with some lobes extravagantly over-developed, like the horrible skulls in Dali’s early paintings.

On Soviet Psychology: [In] the postwar period, a new Soviet psychology, strongly opposed to Freudian and all other Western schools, accepted the [Ivan] Pavlovian idea, merely adding that the consciousness, as ‘animal’ behavior, could be conditioned by outside pressures, or more generally Marxist- notion that socio-economic relations determine consciousness. Like Lysekoist biology, it reflected the Stalinist doctrine that the new order was creating the ‘new Soviet man’ with characteristics different from, and superior to, those of others. This transformation of the human mind, of the human species, appears to have been among Stalin’s most powerful aims and conviction. (pg 299)

Describing Stalin’s Last Years: So Stalin enters his last phase, possessed even more than before by the demons of suspicion and implacability. He was beginning to have bouts of dizziness, and his psychological condition too continued to deteriorate. In 1951, in a moment of insight, Stalin actually said in front of Mikoyan and Khrushchev, though appearing not to notice them, ‘I’m finished, I trust no one, not even myself.’ His daughter writes that in these last years, he had forgotten all human attachments, he was tortured by fears which became a genuine persecution mania, and in the end his strong nerves gave way. But the mania was not a sick fantasy; he knew and understood that he was hated, and he knew why.