Soon after, Kropotkin made his way to England. He challenged Darwin’s followers, most notably Thomas Henry Huxley, and their claims that natural selection almost always led to competition. Yes, Kropotkin admitted, sometimes that happens, especially in the tropics, but mutual aid was just as common, if not more so. It was a biological reality and a political one. “The ant, the bird, the marmot … have read neither Kant nor the fathers of the Church nor even Moses,” Kropotkin wrote. “The idea of good and evil has thus nothing to do with religion or a mystic conscience. It is a natural need of animal races. And when founders of religions, philosophers, and moralists tell us of divine or metaphysical entities, they are only recasting what each ant, each sparrow practices in its little society.”
Kropotkin published a series of books and long pamphlets, including Mutual Aid, The Great French Revolution, Modern Science and Anarchism, and Ethics. He lectured across Europe—in the places that hadn’t banned or expelled him for being a troublemaker—and in two long speaking tours in the United States. He probably would have returned for a third tour, but after President McKinley was assassinated, anarchists were personae non grata in America. Rumors were even floated in the United States with the preposterous notion that Kropotkin was somehow linked to the assassination.
By the first decade of the 20th century, two things still troubled Kropotkin about his theory of the evolution of cooperation. He had been arguing that when environmental conditions changed and mutual aid was especially useful, it seemed to take hold in a population quickly. Really quickly. So quickly that it just couldn’t be accounted for by the slow, gradual changes that Darwinian theory of the day proposed. An evolutionist through and through, Kropotkin turned to the ideas of Jean-Baptiste Lamarck, who had proposed his own ideas decades before Darwin about how evolution operates. Lamarck suggested that habits acquired during the lifetime of an organism could be transmitted to the next generation. For example, if shore birds stretched their muscles as far as possible to raise themselves up on wet sandy beaches, their offspring would have longer legs as a result. With Lamarckian inheritance, massive change can happen in a single generation. That gave Kropotkin the speed he needed to explain how mutual aid increased so quickly. Problem 1 solved. Or so he argued.
Problem 2 was this: In real time, as it was happening, what prompted an animal to dispense mutual aid? Kropotkin turned to economist Adam Smith for insight. Though Kropotkin despised the capitalist system Smith had devised in An Inquiry into the Nature and Causes of the Wealth of Nations, he was enamored with an earlier book of Smith’s called The Theory of Moral Sentiments. In it, Smith made the case that humans dispense mutual aid because we mentally put ourselves in the position of those needing aid, and to “minimize our own vicarious pain” we help—we are empathetic. But Adam Smith restricted his discussion of empathy and mutual aid to humans. When Kropotkin lifted that restriction, he found what he needed. “Adam Smith's only mistake,” Kropotkin wrote, “was not to have understood that this same feeling of sympathy [what today we call empathy] in its habitual stage exists among animals as well as among men.” Problem 2 solved. Or so he thought.
Almost 100 years after Kropotkin’s death, what can we say about his theory of mutual aid? Well, with 20/20 hindsight, he certainly made a mistake aligning himself to Lamarck, but it was a mistake that many, including Darwin, made. And it’s still a matter of heated debate whether nonhumans show empathy. My guess is that some do, but the data are scant. But Kropotkin’s primary legacy in the sciences is that he was in the forefront of challenging the prevailing Darwinian principle that evolution was strictly about competition and survival of the nastiest.
Today, hundreds of papers come out annually on animal cooperation in nonhumans, and many of these papers show Kropotkin to be something of a prophet. But what Kropotkin cared about more than anything was that understanding mutual aid in animals might shed light on human cooperation and perhaps help save humanity from destroying itself. Whether that happens remains to be seen.