Various considerations touching the sciences, ponies, the search for the truth, and doughnuts
Like all the finest cafés in Canterlot, Doughnut Joe's had been the scene of many sophisticated intellectual discussions over the years.
“—so I said to her: Jelly? Are you sure? I mean we can do that—it might be quite fun—but wouldn't you rather have something more fashionable? A nice lavender sorbet or something? And then she said: 'Nothing wobbles quite like a good jelly'. And that was just the second course! You won't believe what she said when we discussed the rest of the menu—Hey Minuette!”
Lemonhearts interrupted the story she was telling Twinkleshine to greet her friend, who had just arrived for their regular morning doughnut break at their favourite shop.
“Hello Lemonhearts. Hello Twinkleshine.”
“I heard Twilight's in town again today. Do you think she'll join us?” said Twinkleshine.
“Yes, I saw her outside the library,” replied Minuette. “She said she would join us as soon as she found Moondancer.”
Lemonhearts giggled.
“Did she get lost in a book again?”
“She gave me this,” said Minuette, levitating a large book onto the table top.
“What is that?” said Twinkleshine. She turned her head to one side to read the title on the spine. “Discourse on the Method? What the hay is that all about?”
“I have no idea,” said Minuette. “But Twilight insisted that we look inside before they arrive.”
Minuette casually flipped the book cover open then let out a shriek.
“Eek!”
“Hi Minuette!” A minimalist depiction of Twilight Sparkle waved a hoof in greeting from the title page. A similar ink image of Moondancer walked onto the page and smiled up at her.
“What?.. You!.. Both of you!.. How'd you do that?”
“It's one of Haycartes' methods,” said Moondancer. “Isn't it great? Twilight taught it to me. You can use it to project yourself into any book. And the obvious one to try it out with was Haycartes' Discourse on Method itself.”
“How?.. What?.. Who is Haycart?”
The two line drawings raised their point-like eyes upwards in unison, with a despairing sigh.
“If any of you had read Obscure Unicorn History,” said Twilight, “then you would know that Reiné Haycartes was a brilliant mathematician, scientist and philosopher from the Equestrian Renaissance. He made outstanding contributions to our understanding of the world, and did so in his own way. Rejecting classical knowledge, he set out travelling around Equestria, seeking to learn from the 'great book of the world'. What he achieved was amazing.”
“For example—turn to page three hundred and sixty-nine,” said Moondancer.
Minuette did as she was told. The moving illustrations of Twilight and Moondancer galloped from page to page as she flipped through the book, eventually arriving at a geometric drawing.
“Haycartes was one of the first ponies to look in detail at how you can form a rainbow from the reflection and refraction of light in rain droplets,” said Moondancer. “He used geometry to show that a rainbow would be formed when sunlight is reflected at forty-two degrees.”[1]
[1] See: The Art of Rainbow Engineering.
“He did a lot of ground-breaking work on geometry and algebra,” said Moondancer. “He developed the Cartesian system of coordinates. But he is best known as the father of modern philosophy.”
“He set out to apply the rigorous methods of mathematics to philosophy,” said Twilight.
“He was a rationalist and a skeptic,” said Moondancer. “He wanted to clear the ground of anything he couldn't be sure about, and build a new philosophical system from scratch. He began by doubting the existence of everything. Asking: How can we be sure that anything really exists when our senses can deceive us? Maybe everypony we see is really a changeling, or the world is just an illusion produced by some demon with a bizarre sense of humour and a liking for pastel colours and cute imagery. Can we ever be sure about anything? But then he realized that he could be sure that he himself must exist, as otherwise he would not be able to doubt it.”
“Hence his most famous saying,” said Twilight. “'I think, therefore, I am.' Or 'Cogito ergo sum' in the classical.”
“Or 'Je pense donc je suis' in his own tongue,” added Moondancer, not to be outnerded.
“I think I can agree with that,” said Minuette. “But what's the big deal?”
“He wanted to establish what he could be absolutely certain of,” continued Moondancer. “So he could use this as a foundation for further thinking. He was then interested in how our power of thought makes us special. He asked the question, if you could build a fully-articulated pony doll, which responded to stimuli, would such an entity be a true thinking pony? He was convinced it would not.”
“He also wrote about anatomy,” said Twilight. “I have a copy of his Treatise on Ponies. He was fascinated by the idea that our bodies were machines, just like the mechanical clocks of his age. The way blood is pumped around the body by the beating of the heart. But he concluded that ponies are more than mechanical automata, as he argued that while a machine could be made to respond to certain stimuli in certain ways, we could always distinguish it from a real pony.”
“But philosophers continue to argue whether that is true,” said Moondancer. “The question has become increasingly relevant with the development of artificial intelligence systems.”
“Haycart was a dualist,” said Twilight. “Whereas some philosophers thought the essence of a pony comes from the biological processes inside our bodies, he felt the mechanical body and the immaterial mind were separate entities which interact with one another. Our mechanical actions are driven by our abstract thoughts.”
The two book horses concluded the lecture with an illustrated hoof bump.
“That makes sense,” said Twinkleshine, with a pensive look. “I first think about eating a doughnut—a thought—then I reach out a hoof to pick it up... But is it different if I levitate it to my mouth?..”
Minuette and Lemonhearts exchanged blank looks.
“I don't know about that,” Minuette said. “But if your mechanical bodies want to eat any doughnuts, and if your immaterial minds want to hear Lemonhearts story about Princess Luna and the jelly, then you're going to have to come out of there and join us.”
Twinkleshine, however, was thinking deeper.
“So...” she said. “If you've magically projected your minds into the book using the Haycartes method... And a key part of Haycartes philosophy is that the body and mind are separate entities... Where are your bodies now?”
Author's Note
Thanks for reading. If you are, perchance, now inspired to read more of the work of René Descartes (1596-1650), his Discourse on the Method can be read online. Unfortunately there doesn't seem to be an English translation available online that includes the supplementary chapters, with the bit about rainbows. If your French is good enough, the original version is: Discours de la méthode.
