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Richard Pettigrew

@wiglet1981.bsky.social

Philosopher at University of Bristol πŸ³οΈβ€πŸŒˆ he/him https://richardpettigrew.com/ Books: Epistemic Risk and the Demands of Rationality | Choosing for Changing Selves | Dutch Book Arguments | Accuracy and the Laws of Credence | Who Are Universities For?

3,466 Followers  |  1,009 Following  |  1,041 Posts  |  Joined: 03.08.2023  |  2.2034

Latest posts by wiglet1981.bsky.social on Bluesky

The β€œI’m watching TED talks!” sign in an SF hotel almost turned me into an arsonist

24.10.2025 03:38 β€” πŸ‘ 102    πŸ” 8    πŸ’¬ 1    πŸ“Œ 0

It was working with the complete class theorem that really got me seeing how strong the pressures are to be a precise probabilist.

23.10.2025 19:01 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

on pain of being dutchbookable/exploitable. So he’s also got to explain why having imprecise credal states and being rational is really functionally different from having precise credal states and being rational?

23.10.2025 18:59 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 2    πŸ“Œ 0

Isn’t there a worry for Jim too? He’s an impermissivist, but about imprecise credal states. So he thinks your evidence fixes your imprecise credal state. But then when he comes to decision theory he’s got to say that actually you pick a particular precise state and always act as if that’s yours,

23.10.2025 18:59 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

I'm extremely pleased to say that my paper "Brazen Dogwhistles" was published today in APA Studies on Feminism and Philosophy! This special issue focuses on @jennysaul.bsky.social's Dogwhistles & Figleaves, with several original papers and replies from Jenny. The whole issue is really fantastic.

23.10.2025 17:05 β€” πŸ‘ 32    πŸ” 9    πŸ’¬ 3    πŸ“Œ 0

The comparison with game theory is illuminating! Thanks, I hadn’t thought of that.

23.10.2025 16:19 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

I’m pretty sympathetic to this. But one striking thing is then that it isn’t very clear how imprecise probabilism differs from a permissivist version of precise probabilism. In each case, one must pick a particular precise probability function and always choose in line with that.

23.10.2025 16:19 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 2    πŸ“Œ 0

In particular, randomising amongst non-rejected options is often impermissible. This raises questions about how to use the guidance of an imprecise decision theory when it leaves different options non-rejected.

23.10.2025 15:09 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

with expected utility theory, thereby coordinating how to pick across different potential decision problems. Some strategies that always pick an option that the decision theory does not reject are deemed impermissible.

23.10.2025 15:09 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Savage-style expected utility theory does not have this flaw; it always deems its own picking strategies to be the rational ones. Popular decision rules for imprecise probabilities never straightforwardly undermine themselves but they often are require adopting strategies that pick in accordance

23.10.2025 15:09 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

For some ways of being uncertain over possible decisions, decision theories that accommodate risk undermine themselves. They simultaneously provide specific advice about what to pick whilst also deeming that very picking strategy to be impermissible.

23.10.2025 15:09 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Abstract: Decision theories give guidance about what to do when you face a particular decision. But they also give higher-level adviceβ€”depending on how likely you think it is that you’ll face various decision problems, decision theories give advice about the best strategy for picking what to do.

23.10.2025 15:09 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0
The view down the Grand Canal from the Accademia bridge

The view down the Grand Canal from the Accademia bridge

This paper with Catrin Campbell-Moore and Jason Konek is now out in Theory & Decision!

Choosing How to Choose

This is the link to the journal version: link.springer.com/article/10.1...

But Springer’s typesetting is so awful, I’d maybe recommend the preprint instead: philarchive.org/rec/PETOCH

23.10.2025 15:09 β€” πŸ‘ 14    πŸ” 2    πŸ’¬ 1    πŸ“Œ 0

I stood behind someone at a hotel reception in Blackpool where they were demanding a full refund of their stay because β€˜the hotel website’ said they had a pool and it doesn’t. β€˜The hotel website’ was Google’s AI Overview and it took ten minutes for the receptionist to explain the difference.

23.10.2025 09:51 β€” πŸ‘ 158    πŸ” 45    πŸ’¬ 1    πŸ“Œ 1
Grey cat peers inquisitively at you. You have failed to respond adequately to their referee comments.

Grey cat peers inquisitively at you. You have failed to respond adequately to their referee comments.

insistent

23.10.2025 08:36 β€” πŸ‘ 8    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Any sense what happened? I’m not a video person so I’ve never really watched her, but people used to speak positively of her a while back, but now this sort of thing seems quite common for her.

22.10.2025 18:48 β€” πŸ‘ 7    πŸ” 0    πŸ’¬ 2    πŸ“Œ 0

A rule of thumb: if people are willing to assume significant risks to cross the channel, they probably are fleeing significant risks in France, and a non-insignificant number will try to recross the channel again if sent back to France. Any one-in-one-out policy must depend on France being safe.

22.10.2025 17:42 β€” πŸ‘ 2    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

Shamelessly promoting my favorite paper. Everybody who was anybody in the history of science/philosophy/mathematics had a view on the moon illusion. frances-egan.org/uploads/3/5/...

02.10.2025 18:23 β€” πŸ‘ 47    πŸ” 16    πŸ’¬ 4    πŸ“Œ 2
Franz Berto on modal realism, imagination and reading the Tractatus I EP 3
YouTube video by Ping Pong Philosophy Franz Berto on modal realism, imagination and reading the Tractatus I EP 3

Pablo of @pingpongphilosophy.bsky.social interviews me for his podcast and I reveal who my favourite living philosopher is (I see y'all on the edge of your seat):

www.youtube.com/watch?v=4KdK...

22.10.2025 09:55 β€” πŸ‘ 5    πŸ” 1    πŸ’¬ 0    πŸ“Œ 0

Tyrtaeus too, I guess? Hard to tell whether that counts as a whole culture, though

22.10.2025 07:37 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

I pray to Chicago Pope that I never do something to anger this man.

22.10.2025 05:00 β€” πŸ‘ 77    πŸ” 6    πŸ’¬ 0    πŸ“Œ 0

Congratulations, Noreen!!

21.10.2025 09:14 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0
Research Associate in Philosophy College of Arts and HumanitiesSchool of HumanitiesΒ Research Associate in PhilosophyVacancy Reference: 184814Salary: Grade 7, Β£41,064 - Β£46,049 per annumΒ We have an opportunity for a Research Associ...

I'm hiring! A 2-year postdoc on my ERC project "KNOW-HOW" at the Cogito: Epistemology Research Centre University of Glasgow. (Deadline for applications 9 November.) Please share with anyone you think might be interested. Details below

www.jobs.gla.ac.uk/job/research...

20.10.2025 17:33 β€” πŸ‘ 38    πŸ” 25    πŸ’¬ 2    πŸ“Œ 1
a large, fluffy pup sits on her human's lap outdoors. she's looking straight ahead while being held like a child. her feet are up and her toe beans are spread wide, presumably for tanning purposes.

a large, fluffy pup sits on her human's lap outdoors. she's looking straight ahead while being held like a child. her feet are up and her toe beans are spread wide, presumably for tanning purposes.

This is Comoong. She has a whole dog park to run around in. Prefers to sit like this the entire time instead. 13/10 (IG: comoongpark)

20.10.2025 19:59 β€” πŸ‘ 4135    πŸ” 439    πŸ’¬ 64    πŸ“Œ 21

Good time to repeat Brett’s story about a child of two professors who referred to their preschool friends as β€˜their colleagues’

17.10.2025 16:57 β€” πŸ‘ 106    πŸ” 7    πŸ’¬ 1    πŸ“Œ 0
Video thumbnail

πŸŽ™οΈ A brand new episode of Ping Pong Philosophy drops TOMORROW!
This week’s guest: Franz Berto πŸ“

πŸ’­ When was the first time you realized that Lewis was a great philosopher, yet deeply mistaken?
Stay tuned to hear Professor Berto’s answer!

20.10.2025 12:02 β€” πŸ‘ 7    πŸ” 2    πŸ’¬ 0    πŸ“Œ 1

The lil french Netflix movie about the louvre heist is going to be excellent.

19.10.2025 23:17 β€” πŸ‘ 1807    πŸ” 104    πŸ’¬ 34    πŸ“Œ 7
Grey cat sticks her head foolishly through the banisters

Grey cat sticks her head foolishly through the banisters

Grey cat balances precariously on the banister

Grey cat balances precariously on the banister

good afternoon

19.10.2025 15:15 β€” πŸ‘ 9    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
Abstract of Birch, PrΓ©cis of The Edge of Sentience.

Abstract of Birch, PrΓ©cis of The Edge of Sentience.

It sounds silly but this new prΓ©cis of The Edge of Sentience is one of my favourite pieces of my own writing. Yes, it's true, you could get chatGPT to summarize my book (and it's open access, so you literally could) - but I do it better! www.wellbeingintlstudiesrepository.org/animsent/vol...

16.10.2025 09:10 β€” πŸ‘ 72    πŸ” 13    πŸ’¬ 3    πŸ“Œ 1

When people used to ask on Twitter which historical figure would have been a main character there most often, it always struck me Pierre Bayle was the clear choice

16.10.2025 09:27 β€” πŸ‘ 5    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

@wiglet1981 is following 20 prominent accounts