In the evolution of human culture from pre-history to the present, changes in ethical values have been driven by the most basic force of all: energy.
In a bold new theory, historian Ian Morris argues that humans have found three main ways to get the energy they need – foraging, farming and fossil fuels – and that in each of these epochs, the dominant energy source sets limits on the kinds of societies that can succeed, and each society in turn rewards specific values.
Small forager bands valued equality but were ready to settle problems violently. In larger farming societies those who valued hierarchy but avoided conflict did best. In huge fossil-fuel societies, the pendulum has swung back toward equality but further away from violence.
But if our fossil-fuel world currently favours open, democratic societies, the ongoing revolution in energy capture may well soon signal a new values shift. If so, what might come next?