...in the latest issue of Nature, some physicists published an empirical refutation of
'realism' -- a viewpoint according to which an external reality exists independent of observation.
They also advocate considering
the breakdown of [...] Aristotelian logic, counterfactual definiteness, absence of actions into the past or a world that is not [sic] completely deterministic.
As far as I can tell, what they actually found is evidence against certain local hidden-variable theories that survived Bell's inequalities. Aristotelian syllogisms and realism (in the above sense) seem to be thrown out by the principle that if you throw out the bath water, you might as well throw out the whole bathroom.
Searching. Mary is in the park, looking for Fred. She recognizes Fred's friend Ted some distance away on the left. Knowing that Fred is often in the park with Ted, she turns that way.
Waiting. Alexandre is waiting for Veronique in a cafe. He's been waiting for several hours now, and is doubtful that Veronique will ever show up. Nevertheless, he thinks it is worth waiting some more.
Mary and Alexandre are acting rationally here, even though Mary does not know that Fred is to the left, and Alexandre does not know that Veronique will ever show up. Even if it turns out that both were wrong, I wouldn't blame them for their decisions.
Sometimes, implicatures appear to survive under embedding. Take
1) the column will fail and the bridge will collapse,
which in a suitable context implicates that (the speaker believes that) the bridge will collapse as a result of the column failing. This implicature is still present if (1) gets embedded in, say, a conditional:
2) if it rains, the column will fail and the bridge will collapse;
3) if the column will fail and the bridge will collapse, you'll be in trouble.
(2) is likely to convey that if it rains, the bridge will collapse as a result of the column failing, and (3) that if the bridge will collapse as a result of the column failing, then you'll be trouble.
Reinventing broken wheels is more fun than patching small punctures in functioning ones. So here are some thoughts on desires that are undistorted by knowing the relevant literature.
It seems that unlike for rational belief, there are very few formal constraints on rational desire. For instance, if you desire A & B, it doesn't follow that you should desire A: I'd like to be beaten up and get a billion dollars compensation for it, but I don't desire to be beaten up. By the same example, you may desire A without desiring the disjunction A v B. More generally, all these principles are invalid for rational desire:
I gave a talk about the Canberra Plan on Tuesday (slides) in which I mentioned that I disagree with Lewis and Kim about the semantics of "pain": they say "pain" denotes whatever occupies the pain role in the species under consideration (or whatever is the relevant kind); I think "pain" rather denotes the property of being in a state that realises the pain role. One of the reasons I gave for my preference is that "pain" would be rather exceptional if it worked as Lewis and Kim believe.
Here is a short paper version of my GAP.6 talk "Modal metaphysics and conceptual metaphysics", to appear in the GAP.6 proceedings. It has a lot less formulas than the talk.
I distinguish two metaphysical projects: modal metaphysics and conceptual metaphysics. I show that the two projects really are distinct, and that Frank Jackson's argument for the opposite conclusion doesn't work. Then I have a closer look at how the projects come apart, and suggest that when they do, the modal project always becomes metaphysically uninteresting. Thus the term "metaphysical modality" is a misnomer: metaphysical entailment only matters for metaphysics insofar as it coincides with conceptual entailment.
I suppose I should say a little more on what I call "modal back-reference", and on the sense in which what a sentence expresses can be conceptually independent of how things are in the actual world: doesn't what a sentence express always depend on what the sentence means? Unfortunately, I don't have a simple and uncontroversial answer to that, so I just ignored this point. Hopefully no-one will notice.
I've fixed the bug where sometimes nodes in the displayed tree overlapped. I also made the proof search faster. Now Pelletier 34 is proved in only a few minutes! (Warning: the tree is huge, and might crash your browser.)
Brian argues that our intuitions about whether an action C causes somebody's continued survival is linked to the applicability of causative notions like "opening", "closing", "protecting", "threatening": if C inadvertently causes the survivor to be threatened but at the same time protects him from the threat, we are more inclined to count C as causing the survival than if C threatens the surviver but at the same time inadvertently causes him to be protected.
Carrie, Joe and Brit have recently commented on Williamson's proposal that modal knowledge is based on counterfactual knowledge. I share their suspicion, partly for the reasons Carrie mentions: the mere fact that statements about necessity and possibility are equivalent to counterfactuals doesn't tell us that the route to knowing the former proceeds via the latter. In fact, the assumption that we have a special cognitive faculty for knowing counterfactuals already seems odd to me. After all, we don't have special faculties for knowing indicatives or negations or conjunctions.
I remember the years when this blog, because I wrote the software myself, received zero comment spam. Now it's about 1500 spam comments a day, and some have recently made it through. So I've stepped up the measures again. Every submitted comment now gets assigned a score based on 1) whether the POST request matches up with a previous GET request of the form page by the same client, 2) whether the client has fetched an image embedded in the form, 3) whether the client supports JavaScript, 4) whether the client supports cookies, 5) whether it took more than 5 seconds and less than 24 hours to fill in the form, 6) whether all form fields (including hidden ones) are submitted, 7) whether several randomly inserted form fields that are turned invisible with CSS have been left blank, 8) whether the submitted text doesn't contain spammy words, and 9) whether the same IP has not recently sent me something with a high spam score. If the score is high, you get a warning; if it is very high, you get blacklisted for 10 minutes and sent into a (mild) tarpit. I hope this combination will trap all the spam while not blocking any legitimate users who have merely turned off, say, images and JavaScript. I've tried it with Lynx and it worked fine. Let me know if you run into any problems.