[The Lyssenko affair: the eclipse of reason].

Trofim Lysenko was a Ukrainian peasant whose malign influence dominated biology in the Soviet Union and its imperium through most of Stalin's reign. Lysenko owed his ascendancy to repeated promises that he would rescue Soviet agriculture from the catastrophic state into which it had sunk, following Stalin's disastrous policy of collectivisation of the farms, and a succession of bad harvests. He claimed to have devised methods of imposing desirable hereditary characteristics on plants, and even of converting one species into another at will. He noisily denounced modern genetics as a bourgeois imposture, a view that resonated well with Marxist doctrine. As Lysenko's power grew he was able to smother scientific debate, and to crush all opposition through the arrest and often execution of many leading scientists. Lysenko's preposterous theories became the accepted orthodoxy in the academies and universities of Eastern Europe, and were greeted with enthusiasm by many Communist intellectuals in the West, not least in France. The Lysenko phenomenon is the most extreme, but by no means the only example of the perversion of science by ideology, often with the acquiescence of the scientific community. Nor can we be confident that nothing of the kind could happen today.