The scriptwriter of ‘Taxi Driver’, Paul Schrader, was educated in strict Calvinism and did not see any film until he was 17. The script emerged from the shock that meant he started living in New York – he was born in Grand Rapids, Michigan – his fascination with the weapons and readings of Sartre’s existentialist ‘La nausea’ and the newspapers of Arthur Bremer, the individual who attempted to assassinate George Wallace, a Democratic presidential…