“The only controls available to those on board were two push-buttons on the centre post of the cabin – one labelled ON and one labelled OFF. The ON button simply started a flight from Mars. The OFF was connected to nothing. It was installed at the insistence of Martian mental-health experts, who said that human beings were always happier with machinery they thought they could turn off.”
Vonnegut, Kurt (1959) The sirens of titan, London:Gollancz; New Ed edition (9 Sep 1999)