REMEMBERING ROBERT CONQUEST: The man who told us so. What the West, and the Soviet Union’s victims, owe to Robert Conquest.

THE intellectual history of the West in the 20th century was dominated by arguments over totalitarianism: its causes, effects—and possible justification. Even after flag-waving supporters of the Soviet Union had dwindled to irrelevance, the conviction that communism was a good idea poorly executed persisted in certain quarters. Others still thought the communist threat overstated, or drew equivalences between crimes committed in the name of socialism and those of Western anti-communism. The position that communism was a monstrously evil system responsible for unprecedented atrocities was held by only a minority of scholars. Robert Conquest, who died on August 3rd, was one of the most eloquent and implacable members of that camp. To the chagrin of his opponents, he turned out to be right.

He did not start out as a scourge of the left. He emerged from a brainy ancient British school as an ardent socialist and a crack shot, and fought for the Republican side in the Spanish civil war (albeit for one day, firing a single round). While at Oxford he joined the Communist Party. But he soon left, disgusted by a party hack who claimed that Britain’s bourgeois leaders could never declare war on Hitler.

Witnessing the lies and terror of the Soviet takeover in Bulgaria in 1947 showed him what Stalinism was like in practice.

So many in the West refused to see, even when it slapped them in the face.