I've been teaching a course on classical epistemology this term, so I've thought
a little about knowledge.
A common judgement in the literature seems to be that knowledge is incompatible
with a certain kind of luck -- the kind of luck we find in Gettier cases. This
is then cashed out in terms of safety: for a belief to constitute knowledge it
must be true in all nearby possible worlds.
While I share the initial judgement, the development in terms of safety doesn't
look plausible to me. It has the wrong kind of structure.
For example, any true belief that concerns a modally robust subject matter is
automatically safe. But such beliefs are not immune from Gettier cases. I'm sure
one can find examples where, say, Newton's laws are used to predict whether two
asteroids will collide, and the laws happen to give the correct answer ('no'),
but they don't predict the correct trajectories; the true reason why the
asteroids won't collide involves some feature of general relativity. Now if
someone in the mid 19th century asked whether the asteroids will collide, and
they used Newton's laws to figure out the answer, then their belief (that the
asteroids won't collide) is justified and true, but it isn't knowledge. And yet
it is arguably true in all nearby worlds.
A Sobel sequence is a sequence of conditionals with increasingly strong
antecedent. Lewis used Sobel sequences to motivate his "variably strict"
analysis of counterfactuals.
For example, intuitively (1) and (2) might both be
true, which seems to contradict a simple strict analysis:
(1) If the US had destroyed its nuclear weapons in 1965, there would have
(2) If every country destroyed its nuclear weapons in 1965, there would
have been peace.
A problem with this argument (pointed out in von Fintel 2001), is that the
intuition about (1) and (2) depends on the order in which the sentences are
considered. If we consider (2) first, and judge that it is true, then (1) looks
at best doubtful.
of Choice" paper has now appeared in Mind.
The paper asks how we should understand an agent's decision-theoretic options.
That is, what are the things whose expected utility we are supposed to maximize?
I think the question is a lot harder than often assumed. For example, I argue
that it won't do to say that the options are certain "willings" or "intentions",
as some authors have suggested.
In many respects, the problem of options mirrors the "input problem" for
Bayesianism: what are the propositions on which rational agents are supposed to
conditionalise (or Jeffrey-conditionalise)?
Friends of singular thought typically assume that in order to have a singular attitude towards an object, one must either stand in a special acquaintance relation to the object, or have a special kind of mental representation for it. Both of these views face a challenge from our practice of attitude reports: we can seemingly attribute attitudes with singular content even if neither condition is satisfied.
In a well-known example from Sosa 1970, the army generals decide that the shortest man should go first. The Sergeant tells Shorty: 'they want you to go first'. Here the generals need not be acquainted with Shorty, and it is doubtful that they must have a "mental file" for him.
So far, we have looked at cases in which an agent has a descriptive belief (e.g., "the creature approaching through the woods is a bear"), which gets reported as a singular belief ("Mary beliefs Mark is a bear"). But sometimes we attribute singular beliefs even though the subject appears to have only a general (quantified) attitude about the relevant individual.
A murder has been committed. The detective has figured out that the culprit probably comes from a certain mountain village. She knows little about that village, but believes that all its inhabitants are poor peasants. You are one of the villagers. We might say:
In chapter 3 of The Powers Metaphysic, Neil Williams presents a nice problem for dispositionalists: the "problem of fit".
Dispositionalists hold that there are fundamental dispositional properties. Now consider a particular rock and a particular glass. The rock might have a disposition to break the glass when thrown at it. And the glass might have a disposition to survive impact of the rock. These dispositions are incompatible: if the rock is disposed to break the glass, the glass can't be disposed to survive the impact. But if dispositions are fundamental, then what prevents the rock and the glass from having the incompatible dispositions? The dispositionalist seems to require a mysterious ban on recombination.
Compare the following three sentences.
(1) I thought my husband was a bear.
(2) Mary thinks her husband is a bear.
(3) I think my husband is a bear.
(1) and (2) are ambiguous between a "de re" reading and a "de dicto" reading. But (3) only seems to have the "de dicto" reading. How come?
According to the semantics I have described in earlier parts of this series, an utterance of (3) is true on its de re reading iff (roughly) there is a suitable role R such that (i) in all the speaker's belief worlds, whatever plays R is a bear, and (ii) in the actual world, the speaker's husband plays R.
The latest issue of The Monist contains an outline of an unpublished paper by Lewis: "Nihil Obstat: An Analysis of Ability", along with a useful commentary by Helen Beebee, Maria Svedberg, and Ann Whittle.
Lewis's analysis of ability goes as follows:
You're able to φ iff, for some basic action
(1) doing it would be φing, and
(2) there is no obstacle to doing it.
It is clear from this analysis, and from the context in which it is presented, that Lewis is only interested in a rather specific sense of 'ability'. He wants to spell out the sense in which we are able to perform particular intentional actions that we don't actually perform, even if the world is deterministic. He is not interested in our ability to regrow injured skin, or in the ability of tardigrades and steel to withstand high temperatures. He also isn't interested in what are sometimes called "general abilities", like my ability to play the piano that I have even when I don't have access to a piano. (At any rate, this kind of ability is not covered by his analysis, and it isn't relevant to compatibilism.)
In the previous post, I have assumed that conversational context somehow determines a unique "suitable role" for each individual under discussion, relative to every epistemic subject. This is an unrealistic assumption.
For example, I believe that Canberra gets cold in winter. But Canberra is known to me as the occupant of many roles. Among other things, I know it as the capital of Australia, as the city in which I lived for most of 2012, and as the destination of my most recent international trip. When I say that I know (or believe) that Canberra gets cold, none of these roles may be particularly salient.
In this post, I'm going to present a first stab of a formal semantics for de re belief reports.
As I explained in the last post, I'm going to assume that for every epistemic subject at every time there is a set of doxastically accessible worlds, representing how the subject takes the world to be. I will sometimes refer to these worlds as the subject's 'belief worlds'.
On that background, we can make the guiding idea behind the Quine-Kaplan model more precise: 'S believes that x is F' is true iff there is a suitable role R such that (1) in all worlds doxastically accessible for S, whatever plays R is F, and (2) in the actual world, x plays R.