<?xml version="1.0" encoding="iso-8859-1"?>

<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">

<channel>
  <atom:link href="http://www.umsu.de/blog/rss.xml?comments=on&amp;mode=excerpt" rel="self" type="application/rss+xml" />
  <title>wo's weblog</title>
  <link>https://www.umsu.de/blog/</link>
  <description>Musings in Analytic Philosophy</description>

  <item>
    <title>Moral fictionalism, cooperation, and motivation</title>
    <link>https://www.umsu.de/blog/2026/834</link>
    <guid>https://www.umsu.de/blog/2026/834</guid>
    <pubDate>Tue, 18 Aug 2026 13:16:33 +0000</pubDate>
    <description><![CDATA[Gerritsen
2023 raises a good worry about revolutionary moral fictionalism,
as advocated in Joyce
2001.
The (revolutionary moral) fictionalist says that our naive moral
practice rests on the mistaken assumption that there are
mind-independent moral facts. There are no such facts. But this doesn't
mean that we should stop caring about morality. It is in our personal
interest, according to the fictionalist, to adopt a fiction of morality
and continue talking and acting much like before.
Gerritse...]]></description>
  </item>
    <item>
    <title>Logical omniscience: beyond fragmentation and impossible worlds</title>
    <link>https://www.umsu.de/blog/2026/833</link>
    <guid>https://www.umsu.de/blog/2026/833</guid>
    <pubDate>Fri, 31 Jul 2026 13:38:25 +0000</pubDate>
    <description><![CDATA[Standard Bayesianism assumes that agents are "logically omniscient":
they assign credence 1 to all necessary truths. This seems wrong.
But we need to be clear about the data (as Stalnaker has emphasized,
for example in 1991 and 1999). It's
not a datum that we don't give credence 1 to all necessary truths.
"Credence" is a theoretical term. The data that cast doubt on logical
omniscience are things like this:

I utter "I don't know the 12th digit of pi".
I utter "I'm more confident that the 12t...]]></description>
  </item>
    <item>
    <title>Coded communication</title>
    <link>https://www.umsu.de/blog/2026/832</link>
    <guid>https://www.umsu.de/blog/2026/832</guid>
    <pubDate>Fri, 26 Jun 2026 14:42:55 +0000</pubDate>
    <description><![CDATA[Imagine a community of people who pass encrypted messages to one
another, without knowing what they mean. Agent X has encrypted a message
and handed it to messenger A, who passes it to messenger B, who passes
it to agent Y, who has the codebook to decrypt the message. When A
utters the message to B, she has no idea what it says; neither does
B.
Intuitively, the meaning or content of A's
utterance is the content of the decrypted message. That's why A and B
don't know what the utterance means.
...]]></description>
  </item>
    <item>
    <title>Lewis 1969 on the probability of conditionals</title>
    <link>https://www.umsu.de/blog/2026/831</link>
    <guid>https://www.umsu.de/blog/2026/831</guid>
    <pubDate>Thu, 18 Jun 2026 11:02:08 +0000</pubDate>
    <description><![CDATA[I finally got around to adding the papers from Janssen-Lauret and Macbride
2023 to the search corpus at https://www.david-lewis.org. It's
a wonderful collection with lots of treasures. I want to comment on an
intriguing passage on pp.71f., from an abandoned 1969 textbook project
on confirmation theory.
First, some context. At this point in the manuscript, Lewis has
introduced \(\mathcal{M}\) as a
probability measure on the propositions expressible in a language \(\mathcal{L}\) with classical ...]]></description>
  </item>
    <item>
    <title>Comment by David Duffy on 'Time travel and sortal-relative predication'</title>
    <link>https://www.umsu.de/blog/2026/830#c2477</link>
    <guid>https://www.umsu.de/blog/2026/830#c2477</guid>
    <pubDate>Tue, 09 Jun 2026 00:26:45 +0000</pubDate>
    <description><![CDATA[One image that followed the spread of the concept of space-time was of a human being as a &quot;worm&quot; extended in the t direction in the Parmenidean block universe. Eternalists would label Tim as a hairpin structured region, I guess, and time travel probably make best sense in that framework.]]></description>
  </item>
    <item>
    <title>Time travel and sortal-relative predication</title>
    <link>https://www.umsu.de/blog/2026/830</link>
    <guid>https://www.umsu.de/blog/2026/830</guid>
    <pubDate>Mon, 08 Jun 2026 13:49:59 +0000</pubDate>
    <description><![CDATA[Here's an attractive picture. All there really is, at a fundamental
level, are fields in spacetime (or something like that). The world as we
know it, with its rocks and chairs and cats and people, somehow emerges
from this basis: all truths about rocks and chairs etc. are made true by
truths about fields in spacetime. But how? To explain this, it would
help if we could locate the familiar objects – rocks and chairs etc. –
in the physical description of reality. With the help of classical
...]]></description>
  </item>
    <item>
    <title>Comment by Aram Harrow  on 'De Finetti's theorem without symmetries?'</title>
    <link>https://www.umsu.de/blog/2025/815#c2476</link>
    <guid>https://www.umsu.de/blog/2025/815#c2476</guid>
    <pubDate>Sun, 31 May 2026 06:01:16 +0000</pubDate>
    <description><![CDATA[I wrote a paper with a version of a de Finetti theorem without symmetry:<br />
 arxiv.org/abs/1310.0017<br />
<br />
<br />
There&#039;s a lot of quantum stuff you can ignore. The &quot;dF without symmetry&quot; theorem is self contained.]]></description>
  </item>
    <item>
    <title>Comment by wo on 'Teaching mathematical logic'</title>
    <link>https://www.umsu.de/blog/2026/829#c2475</link>
    <guid>https://www.umsu.de/blog/2026/829#c2475</guid>
    <pubDate>Mon, 11 May 2026 14:54:54 +0000</pubDate>
    <description><![CDATA[No, sorry, I didn&#039;t write up the solutions.]]></description>
  </item>
    <item>
    <title>Comment by Harriet Baber on 'Teaching mathematical logic'</title>
    <link>https://www.umsu.de/blog/2026/829#c2474</link>
    <guid>https://www.umsu.de/blog/2026/829#c2474</guid>
    <pubDate>Sun, 10 May 2026 18:28:21 +0000</pubDate>
    <description><![CDATA[Are there solutions to the exercises? I looked through but couldn&#039;t find.]]></description>
  </item>
    <item>
    <title>Comment by Alexander Pruss on 'Gödel, Mechanism, Paradox'</title>
    <link>https://www.umsu.de/blog/2025/823#c2473</link>
    <guid>https://www.umsu.de/blog/2025/823#c2473</guid>
    <pubDate>Mon, 20 Apr 2026 14:47:08 +0000</pubDate>
    <description><![CDATA[Here&#039;s a variant that uses a non-factive operator (inspired by Modal Liars). Let P be epistemic possibility, e.g., understood as consistency with what I know. Construct G such that PA proves: G iff ¬P(⌜G⌝). Suppose G. Then G is not consistent with what I know. But all truths are consistent with what I know. So, ¬G. So P(⌜G⌝). But now this looks paradoxical: surely I know ¬G, having seen the proof, so G isn&#039;t consistent with what I know. Fun!

I think it&#039;s a bit har...]]></description>
  </item>
    <item>
    <title>Comment by wo on 'Gödel, Mechanism, Paradox'</title>
    <link>https://www.umsu.de/blog/2025/823#c2472</link>
    <guid>https://www.umsu.de/blog/2025/823#c2472</guid>
    <pubDate>Mon, 20 Apr 2026 10:49:27 +0000</pubDate>
    <description><![CDATA[Nice! <br />
<br />
More generally, the fact that knowledge entails truth makes it not too surprising that sentential accounts of knowledge (knowledge predicates that apply to sentences, rather than e.g. sets of worlds) run into paradox. My interest in paradoxes for sentential belief stems partly from trying to show that the paradoxes for sentential attitudes don&#039;t simply piggy-back on the Liar.<br />
]]></description>
  </item>
    <item>
    <title>Comment by Alexander Pruss on 'Gödel, Mechanism, Paradox'</title>
    <link>https://www.umsu.de/blog/2025/823#c2471</link>
    <guid>https://www.umsu.de/blog/2025/823#c2471</guid>
    <pubDate>Mon, 20 Apr 2026 01:01:05 +0000</pubDate>
    <description><![CDATA[Another thought on your formalized Knower. It feels very close to just a formalized contingent Liar. Here&#039;s why. Start by noting that K(p) is something like T(p)∧JBPlus(p) (knowledge is true justified belief plus). Let K*(p) be T(p)∧M(p) for any contingent M(p). The same argument gives ¬K*(⌜G⌝) and G for an analogous G to yours. But if G, then T(⌜G⌝). (This is the more controversial half of the T-schema, so one could push back, which is why I used the weasel phrase &quot;ver...]]></description>
  </item>
    <item>
    <title>Comment by wo on 'Gödel, Mechanism, Paradox'</title>
    <link>https://www.umsu.de/blog/2025/823#c2470</link>
    <guid>https://www.umsu.de/blog/2025/823#c2470</guid>
    <pubDate>Sun, 19 Apr 2026 05:53:36 +0000</pubDate>
    <description><![CDATA[@Alexander: Thanks.

Maybe you&#039;re right that we can&#039;t fully grasp the meaning of G, although (1) by the MRDP theorem there&#039;s a version of G that&#039;s &quot;just&quot; a diophantine equation, and (2) I&#039;m not sure how much is required to grasp the meaning of a mathematical statement in general. But more importantly (as you mention) the paradox returns if we reason about the knowledge of smarter agents, so I still think it cautions against assuming that we have a clear gr...]]></description>
  </item>
  </channel>
</rss>
