“I am ashamed at the number of things around my house and shops that are done by … human beings,” Thomas Edison once remarked. “Hereafter a motor must do all the chores.” Much labor-saving has been done, but much remains in an environment of energy and economic freedom. Think automation, which is still in its infancy, and the AI revolution.

Labor Day provides an opportunity to appreciate how inanimate energy has improved productivity and increased leisure. Energy is defined as the capacity to do work. Work is labor, and the more done by inanimate energy, the greater the reward.

For much of human history, the ability to do work was limited by the strength of men, women, children, and animals. But by harnessing massive amounts of energy through machine work, the amenities of modern life sprang into being.

A life of opulence once took hundreds of human helpers. Approximately 500 were required to create meals for King Louis XIV at Versailles in 1700. Today, the typical supermarket has far more food choices than available to this ruler living in the world’s richest palace.

Today’s energy-powered transportation and communications options would be unimaginable to the richest of yore. Who, for example, does not have a cell phone for instant communication with the rest of the world? In contrast, John D. Rockefeller and leading industrialists of his era were informationally isolated.

How many human laborers would it take to approach the energy consumed by the average American? If a fit person averages a sustained output of about one-tenth of a horsepower, the translation would be around 150 servants working round-the-clock to match the spent inanimate energy. And still much could not be done.

The transition from human power to animal power to machine power has made energy the master resource. The labor-enhancing, labor-saving characteristic of energy-enabled machinery was described by Erich Zimmermann in the mid-twentieth century as follows:

The shift to machine power changed America from a rural agricultural nation to an industrial giant. It also made men’s lives easier and richer. In 1850, the average American worked seventy hours a week. Today he works forty-three. In 1850, our average American produced about 27 cents’ worth of goods an hour. Today he produces about $1.40 worth in dollars of the same purchasing power.

“By providing energy flows of high power density, fossil fuels and electricity made it possible to embark on a large-scale industrialization,” noted energy polymath Vaclav Smil, “creating a predominantly urban civilization with unprecedented levels of economic growth reflected in better health, greater social opportunities, higher disposable incomes, expanded transportation and an overwhelming flow of information.”

The benefits of modern energy contribute to days off to relax and celebrate and to eventual retirement from work for older Americans. This Labor Day, recognize and appreciate energy exceptionalism.