Lewis's father, a successful builder and architect, came from a Welsh farming family, and was a very devout Methodist.
Here, his leftist political sermons attracted a large youth following, but upset a group of older, more conservative members.
He also became involved in work to support the unemployed, and served on the local Trades Union Council.
Lewis quit his ministry in Ipswich to take on the task of building a national network of discussion groups.
The groups brought together in a progressive movement intelligent, literate people who had not found rewarding political action in left-wing parties.
"Reply to John Lewis" first appeared, translated by Grahame Lock, in two numbers of the theoretical and political journal of the Communist Party of Great Britain, Marxism Today, in October and November 1972.
As Althusser himself noted: "'Reply': because, a few months earlier (in its January and February numbers of 1972), the same journal had published a long critical article by John Lewis (a British Communist philosopher known for his interventions in political-ideological questions) under the title: 'The Althusser Case'.