The German mathematician Gottfried Wilhelm Leibniz (1646–1716) is perhaps best remembered in science as the co-inventor (with Newton) of the differential calculus. In our story, however, he has a presence not so much because, like his great French contemporary the philosopher Blaise Pascal (1623–1662), he built a calculating machine—in Pascal’s case, the machine could add and subtract, whereas Leibniz’s machine also performed multiplication and division—but for something he wrote vis-à-vis calculating machines. He wished that astronomers could devote their time strictly to astronomical matters and leave the drudgery of computation to machines, if such machines were available. Let us call this Leibniz’s theme, and the story I will tell here is a history of human creativity built around this theme. The goal of computer science, long before it came to be called by this name, was to delegate the mental labor of computation to the machine. Leibniz died well before the beginning of the Industrial Revolution, circa 1760s, when the cult and cultivation of the machine would transform societies, economies, and mentalities. The pivot of this remarkable historical event was steam power. Although the use of steam to move machines automatically began with the English ironmonger and artisan Thomas Newcomen (1663–1727) and his invention of the atmospheric steam engine in 1712, just 4 years before Leibniz’s passing, the steam engine as an efficient source of mechanical power, as an efficient means of automating machinery, as a substitute for human, animal, and water power properly came into being with the invention of the separate condenser in 1765 by Scottish instrument maker, engineer, and entrepreneur James Watt (1738–1819)—a mechanism that greatly improved the efficiency of Newcomen’s engine. The steam engine became, so to speak, the alpha and omega of machine power. It was the prime mover of ancient Greek thought materialized. And Leibniz’s theme conjoined with the steam engine gave rise, in the minds of some 19th-century thinkers, to a desire to automate calculation or computation and to free humans of this mentally tedious labor.
VI. On the geometrical representation of the expansive action of heat, and the theory of thermo-dynamic engines