Note: This is one of a series of posts adapted from my new book, Darwin Day in America. You can find other posts in the series here.

This week’s installment of “Meet the Materialists” is particularly fitting for the week of Halloween.

By the turn of the nineteenth century, Italian scientist Giovanni Aldini was performing macabre experiments on decapitated oxes, horses, lambs… and humans. “The unenlightened part of mankind are apt to entertain a prejudice against those… who attempt to perform experiments on dead subjects,” Aldini later acknowledged, but he maintained that such experiments were justified because the object was to improve human welfare. “It is… an incontrovertible fact, that such researches in modern times have proved a source of the most valuable information.”

Determined to understand the workings of what he called “the human animal machine,” Aldini knew that he needed to procure bodies while they were still fresh and “retained… the vital powers in the highest degree of preservation.” His solution? “I was obliged, if I may be allowed the expression, to place myself under the scaffold, near the axe of justice, to receive the yet bleeding bodies of unfortunate criminals, the only subjects proper for my experiments.”

Aldini’s first human experiments were conducted on the bodies of two young brigands who had been decapitated in Bologna in January 1802. Aldini started by applying electricity to various parts of their decapitated heads. This produced “the most horrid grimaces. The action of the eyelids was exceedingly striking.” Through further applications of electricity, the mouth of one of the heads generated a small amount of saliva, and the tongue moved back into the mouth after having been pulled out. Aldini also dissected the brains and applied electricity to their various components, producing further facial convulsions. Finally, Aldini applied electricity to the trunks of the bodies, which resulted in one of the corpses raising its forearm — “to the great astonishment of those who were present.”

By 1803, Aldini was in London experimenting on the body of a British criminal who had been hanged. Aldini praised the “enlightened” British legislators who permitted the bodies of criminals executed in England to be handed over for medical experimentation. His British experiment “surpassed our most sanguine expectations,” he later wrote enthusiastically, adding that it had been so successful “vitality might, perhaps, have been restored, if many circumstances had not rendered it impossible.” Aldini’s experiments sparked imitators as scientists across Europe rushed to discover the secret of animation.

Aldini’s gruesome experiments provided one of the inspirations for Mary Shelley’s Frankenstein, and even possibly for C.S. Lewis’s That Hideous Strength. But even more important, as I explain in Darwin Day in America, Aldini’s experiments foreshadowed the rise of a virulent strain of materialism that attempted to use science to reduce human beings and their very thoughts to mere matter in motion. The full story of the development of this “scientific materialism” can be found in my new book Darwin Day in America in chapter 1, “Nothing Buttery from Atomism to the Enlightenment,” and chapter 2, “Darwin’s Revolution.”

To order Darwin Day in America click here. To find out more information about the book (and watch the trailer), visit the book’s website here.