These are not sentimental considerations; they constitute the mechanism of production and therefore of power. Personal liberty is the pre-condition of the release of energy. Private property is the inductor which initiates the flow. Real money is the transmission line; and the payment of debts comprises half the circuit. An empire is merely a long circuit energy-system. The possibility of a short circuit, ensuing leakage and breakdown or explosion, occurs in the hook-up of political organization to the productive processes. This is not a figure os speech or analogy, but a specific physical description of what happens.

p. 62 - The God of the Machine (1943)