Generational

Summary

Aaron Mahnke's Cabinet of Curiosities

Episode: Generational

Date: May 19, 2026
Podcast: iHeartPodcasts and Grim & Mild

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Episode Overview

In “Generational,” Aaron Mahnke guides listeners through two captivating historical vignettes examining the power of legacy—one political, one scientific. The first story explores the rise and fall of the Stuart monarchy and Oliver Cromwell, focusing on the posthumous fate of their severed heads and the divergent ways English society wielded these symbols. The second tale profiles Erasmus Darwin, a doctor, inventor, and early evolutionary thinker whose ideas seeded the eventual work of his grandson, Charles Darwin. Both stories meditate on the way ideas and reputations echo through generations, sometimes in surprising or tragic ways.

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Story One: The Fates of Kings (00:38–06:00)

Main Points

• Tumult in 17th-Century England:
  Political and religious friction grows as Puritan Parliament opposes the Stuart monarchy’s perceived drift towards Catholicism.

• English Civil War (1642–1649):

  • King Charles I’s attempt to arrest members of Parliament sparks war.
  • Royalist defeat leads to Charles’s execution—a potent, public act meant as deterrence.

• Oliver Cromwell’s Ascendancy and Legacy:

  • Cromwell, once a farmer and Parliament officer, becomes Lord Protector.
  • After his 1658 death, royalist sentiment resurges; Parliament orders Cromwell’s exhumed corpse punished as a traitor.

• Heads on Display—Meanings and Messages:

  • Both Charles I’s and Cromwell’s heads are displayed publicly, but for opposing symbolic purposes:
    • Charles I: Legitimize the new republic.
    • Cromwell: Erase the republican experiment and shore up the monarchy’s restored claim.

• Ends and Afterlife:

  • Charles I’s head ultimately finds closure in a royal tomb; Cromwell’s vanishes, a ghostly legacy.

Memorable Quotes

• “Both heads were exhibited in highly visible civic locations, ensuring that the largest possible number of ordinary citizens would witness the stark warning.” — Aaron Mahnke (05:13)
• “Charles I's head was shown immediately after his death... Cromwell's head, by contrast, was displayed years after his burial, precisely to delegitimize the republican experiment that he had embodied.” — Aaron Mahnke (05:35)
• “The most striking difference... was probably how they were treated after they were on display... Charles I’s head was buried in consecrated ground... Cromwell’s head, on the other hand, simply vanished, reflecting the monarchy’s intention to erase his legacy entirely.” — Aaron Mahnke (05:54)

Key Segment Timestamp Highlights

• 00:47–03:50: Background on the Civil War and execution of Charles I
• 03:50–05:54: Cromwell’s posthumous fate and the symbolism of both executions

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Story Two: Erasmus Darwin’s Inheritance (06:35–12:37)

Main Points

• The Life and Passions of Erasmus Darwin:

  • A large, outwardly gruff, but inwardly happy physician and inventor in late 18th-century England.
  • Equally devoted to medical practice and relentless tinkering, such as designing plans for self-propelled carriages.

• Empiricism in Action:

  • Erasmus relies on careful observation—both in his garden and in his medical practice.
  • He makes connections between inherited traits in plants and humans, noticing patterns that extend across species.

• Influence and Community:

  • Declines being royal physician to pursue experimentation.
  • Sits among the Lunar Society, with friends like Josiah Wedgwood, discussing everything from the abolition of slavery to the education of women.

• Early Evolutionary Theory:

  • Erasmus contemplates common ancestry and species variation.
  • His radical idea: “...in the great length of time since the earth began to exist, perhaps millions of years, that all warm-blooded animals have arisen from one living filament.” (11:39)
  • Publishes these thoughts in Zoonomia—a work underappreciated in his lifetime.

• Generational Ripples:

  • Decades later, Erasmus’s grandson, Charles Darwin, is inspired by these ideas and develops his own theory of evolution that reshapes science.

Memorable Quotes

• “As far as Erasmus was concerned, the only difference between a doctor and a shaman was observation—whether a plant was actually effective at treating the disease in question.” — Aaron Mahnke (07:18)
• “Both were the product of their parents. Only one had inherited traits that were useful, and the other had inherited traits that were harmful.” — Aaron Mahnke, revealing Erasmus's insight into hereditary biology (08:18)
• “Would it be too bold to imagine that in the great length of time since the earth began to exist, perhaps millions of years, that all warm-blooded animals have arisen from one living filament?” — Erasmus Darwin, quoted by Mahnke (11:39)

Key Segment Timestamp Highlights

• 06:35–07:18: Introduction to Erasmus Darwin’s character and methods
• 08:18–09:30: Musings on inheritance and variation; connecting garden observations with human medicine
• 10:24–11:39: The Lunar Society, social causes, and support for Erasmus’s writing
• 11:39–12:14: Erasmus’s Zoonomia and its understated legacy

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Notable Moments

• Parallel and Contrast: The mirror-image fates of Charles I and Cromwell—how England used public executions and displays as political theater.
• Erasmus’s Missed Recognition: The foundational evolutionary insight nearly lost to history, only later revived by a more famous descendant.
• The Lunar Society’s Progressive Spirit: Science, poetry, abolitionism, and the pursuit of women’s education discussed side-by-side.

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Takeaways

“Generational” dives deep into how symbolic gestures (the treatment of a king's and a lord protector’s head) and quietly powerful ideas (the overlooked genius of Erasmus Darwin) can echo across time, shaping the destinies both of nations and of families. In the worlds of power and thought alike, history’s most curious legacies sometimes wait generations to reveal their impact.

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[End of Main Content]

Transcript

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[Narrator (Cabinet of Curiosities)]

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Welcome to Erin Menke's Cabinet of Curiosities, a production of iHeartRadio and Grim and mild.

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Our world is full of the unexplainable. And if history is an open book, all of these amazing tales are right there on display, just waiting for us to explore. Welcome to the Cabinet of Curiosities. It had been a tumultuous decade in England. For generations, the Stuart monarchs had reigned over England, claiming a divine right to rule the nation. Their authority came straight from God himself and thus should not be questioned. Parliament at the time had become increasingly Puritan. And so when King Charles I married the French Catholic Henrietta Maria and his support of an Anglican high church was redoubled, they worried about a backslide into Roman Catholicism. Tensions between the Crown and the Parliament grew until 1642, when the king tried to arrest five members of the House of Commons, widely considered an assault and on its constitutional privilege. Negotiations between parties fell apart, and on August 22nd of 1642, Charles declared war on Parliament. The civil war that erupted as a result would last for two whole years and exposed the deep divides in politics and religion that had long been simmering in England. In the end, the Royalist army was defeated and Charles was captured by Parliament's forces. In victory, Parliament faced a massive dilemma. What exactly do we do with the king? Debate raged on for months before a grim decision was finally made. On January 30th of 1649, Charles I was brought to London Bridge, where, in front of a crowd of his former subjects, London's official executioner, Richard Brandon, ended the King's life with an Axis blow. The head was was displayed on a spike to deter any royalists from further action. Eventually, it made its way to the Tower of London, where it was placed into storage. In the coming years, another would rise to take the mantle of leader of the Commonwealth. One Oliver Cromwell, a farmer and a senior officer in the Parliamentarian army, who rose to claim the mantle of lord protector. In 1653, his Puritan administration championed religious tolerance. Although brutally cracked down on royalist descent, wherever it reared its head, and conspiracies to reinstate the royal line were many. The beheading of Charles I cast a long shadow over the political landscape. Cromwell would rule until his death in the autumn of 1658 after a stroke left him incapacitated. With its figurehead gone, Parliament was once again leaning toward royalist sentiments. Within days of the Lord Protector's death, a measure was passed. Oliver Cromwell's corpse was a traitor. And so a posthumous execution was ordered for the dead man, who was exhumed and summarily beheaded. And as with Charles skull displayed at the palace of Westminster now as a warning to those who may try to carry on Cromwell's republican tradition, it would be displayed there for nearly two years. As the Stuart monarchy reclaimed the throne after the coronation of Charles II In 1660, the head was removed from its public perch, boxed up, and placed in St. George's Chapel at Windsor Castle with the thought that its gruesome reminder was no longer necessary. It would remain hidden until 1685, after Charles II's brother, James II took the throne. You see, it was during his reign that yet another uprising took place. And although it was quelled, Cromwell's head was brought back out and put on display at the Tower of London, just to be safe. And after that, the head vanished from official inventories, its ultimate fate shrouded in mystery. And looking at these two gruesome spectacles, several striking parallels and contrasts emerge. Both heads were exhibited in highly visible civic locations, ensuring that the largest possible number of ordinary citizens would witness the stark warning. Yet the timing of the displays was diverged dramatically. Charles I's head was shown immediately after his death, serving to legitimize a brand new commonwealth and to signal that the old order had been broken. Cromwell's head, by contrast, was displayed years after his burial precisely to delegitimize the republican experiment that he had embodied and to try to reinforce the restored Stuart claim to divine right. But the most striking difference of all between those heads was probably how they were treated after they were on display. The Charles I's head was buried beneath the floor of St. Peter ad Vincula, a gesture of royal clemency that allowed the King's remains to rest in consecrated ground. Cromwell's head, on the other hand, simply vanished, reflecting the monarchy's intention to erase his legacy entirely.

[Liberty Mutual Advertiser]

And, Doug, there's nowhere I wouldn't go to help someone customize and save on car insurance with Liberty Mutual, even if it Means sitting front row at a comedy show.

[Liberty Mutual Advertiser's Friend]

Hey, everyone, check out this guy and his bird. What is this, your first date?

[Liberty Mutual Advertiser]

Oh, no. We help people customize and save on car insurance with Liberty Mutual together. We're married. Me to a human, him to a bird.

[Liberty Mutual Advertiser's Friend]

Yeah, the bird looks out of your league.

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[Narrator (Cabinet of Curiosities)]

Erasmus was a large, friendly man. Although his face didn't always show it, his features tended to droop and make it look like he was scowling. But in truth, he had never been happier in his life. The year was 1790, and he was living with his second wife and their children in their home in Derbyshire, England. Although he was a doctor by trade, he also had a second passion. Invention. He was seated now in his workshop, sketching plans for a combustion device that could be used to propel carriages. He already tinkered with his existing carriage, making it sturdier and easier to steer. Now he wondered if he could get it to move on its own without horses. But this invention would have to wait. The sun was rising, and he needed to get out to his garden to observe his plants. Now, that might sound boring to you and I, but natural observation had always been an important part of Erasmus medical practice. Because as far as Erasmus was concerned, the only difference between a doctor and a shaman was observation as to whether a plant was actually effective at treating the disease in question. Keeping an open mind, but also doing empirical research allowed Erasmus to find success treating people who other doctors hadn't been able to help. For example, back in the 1760s, he had become so well known for this approach to medicine that the king himself asked Erasmus to be his personal physician. But Erasmus declined. He wanted to have time to focus on his experiments. Looking at a thorn apple plant growing in his garden, he was pleased at how well it was doing. Erasmus had learned to cultivate plants by splicing different samples to create the strongest possible plant. It was the kind of thing that humanity had done for thousands of years. But now he was putting these plants to the greatest possible use. After his work in the garden was done, he spent his afternoon at his medical practice, attending to patients. He saw one man who he felt quite bad for because thus far, he'd been unable to help him. The span was large, like Erasmus himself, but unlike Erasmus, he had poor circulation and stamina. His heart seemed to be struggling. In the past, Erasmus had also treated this man's father, who had died from a similar condition. The father ate as much as Erasmus and was also quite Large. And so it seemed to this doctor that the father had passed this propensity toward overeating onto his son. Erasmus worried that he had done the same to his own children. But as he checked the man's vitals, a startling link formed in his mind between the thorn apple in his garden and the man on his exam table. Both were the product of their parents. Only one had inherited traits that were useful, and the other had inherited traits that were harmful. And while the plant and its offspring would endure, this patient, sadly, would not. Much of the plant and animal kingdom that Erasmus had observed behaved in a similar way. Each species produced variations, the most adaptable of which survived and even evolved into new species. It had struck him as odd that so many plants and animals all seemed to be a variation of one another. Even humans themselves were a sort of variation on a chimpanzee, if one observed how similar the two species were. And so that night, Erasmus took his idea to the latest meeting of the Lunar Society, A group of scientists and inventors that he was friends with. His friend Josiah Wedgwood was present. Josiah was a businessman who always encouraged Erasmus endeavors, including his writing of poetry, and which had in fact led to him becoming the most popular poet in England, on top of all of his other accomplishments. Josiah thought that Erasmus theory that all life might somehow be connected in some way was quite interesting and told him that he should expand on it in a book. Encouraged, Erasmus decided to do just that. They spent the rest of the meeting discussing the abolition of slavery and the education of women, two causes the society supported. But they were having trouble gaining traction for in English society. And over the next few years, Erasmus expanded on his ideas in his two volume work, Zoonomia, where he detailed his understanding of anatomy and how to treat various illnesses. And in the book, this is something that he would it be too bold to imagine that in the great length of time since the earth began to exist, perhaps millions of years, that all warm blooded animals have arisen from one living filament. Sadly, the book didn't gain much traction during his lifetime. Decades later, though, long after Erasmus death, his grandson Charles began to research his grandfather in an attempt to get to know him. Erasmus ideas inspired Charles own research and eventually, through observing animal and plant life, Charles put forth his own theory of evolution. Curiously, it was Erasmus Darwin and not his grandson Charles who first thought of the foundational scientific theory. Erasmus was a polymath, someone who is knowledgeable about a variety of things. For all his accomplishments, though, it was the writing least admired. In his own lifetime that contained his greatest ideas. I hope you enjoyed today's guided tour through the Cabinet of Curiosities. This show was created by me, Aaron Manke, in partnership with iHeart Podcasts, researched and written by the Grim and Mild team and produced by Jesse Funk. Learn more about the show and the people who make it [e-mail] curiosities. You'll also find a link to the official Cabinet of Curiosities hardcover book available in bookstores and online, as well as ebook and audiobook. And if you're looking for an ad free option, consider joining our Patreon it's all the same stories but without the interruption. For free, a small monthly fee. Learn more and sign up [e-mail] grimandmild and until next time, stay curious.

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