As the long as the dopamine river keeps flowing, the regime can rule the water. The regime’s control is omnipotent and menacing; with the flick of a finger, it can relax, restrict, tighten, and enhance the supply of bread and circuses to the population.

This classic warning from Huxley was echoed by Lord Sumption on BBC Radio Four last week when he reminded the public that free societies become tyrannies often because the people relinquish their liberties, rather than have them taken by force.