Wednesday, January 31, 2018

Mrs Fox's feelings

Basking in the warmth of Heaven, she floats weightless and naked, far far above the factory chimneys and church spires of the world, in the upper reaches of a sultry sky. It's an intoxicatingly fragrant atmosphere, surging and eddying with huge gentle waves of wind and pillowy clouds – nothing like the motionless, transparent oblivion she'd always imagined Paradise would be. It's more like a breathable ocean, and she treads the heavy air, narrowing the distance between her body and that of her man who's flying beside her. When she's close enough, she spreads her thighs, wraps her arms and legs around him, and opens her lips to receive the incarnation of his love.
Michel Faber, The Crimson Petal and the White, 671

Sunday, January 21, 2018

Very High credence is Not belief


Imagine a spherical die with thousands of tiny faces. You can roll the die around in your hand, surveying all the faces and thinking, of each face, how unlikely it is to end up on top when you roll the die, but that it might. For each face, you have a very high credence in the proposition that it will not end up on top, but it seems that you do not believe that it will not end up on top; it seems so because for some such face you are not at all surprised when it does end up on top.

What would be surprising would be guessing which face it was before it ended up on top; and doing so repeatedly would be so surprising it would suggest some sort of trickery (or psychic power) was present. But that is, of course, quite different; and similarly, the fact that it is unsurprising that our beliefs should sometimes turn out to have been false is a different thing entirely.

The thing is, the Lockean assumption that belief is sufficiently high credence is similarly refuted by almost all of our quotidian beliefs. Consider an ordinary view from some window, for example:

The chance of any particular arrangement of cars, leaves et cetera is low, and so your expectation of having that view is low. Conversely, your expectation of not having that view, and your credence that you won't have that view, are high. But it is of course not the case that you tacitly believe that you won't have that view. On the contrary, you know that you will probably have some such unsurprising view.

Now, a high credence for each possible view not being the actual view is quite compatible with a high credence of one of them being it, of course; but not only is that compatibility paradoxical given the Lockean assumption (it is then the Preface paradox), I just do not believe that anyone really did tacitly believe, before they looked, that the particular possible view that would turn out to have been the actual one was not going to be the actual view. They just are not ever surprised by such an ordinary view.

Friday, January 19, 2018

Turri's Maxwell's Car

When Maxwell arrives at work in the morning, he always parks in one of two spots: C8 or D8. Half the time he parks in C8, and half the time he parks in D8. Today Maxwell parked in C8. It’s lunchtime at work. Maxwell and his assistant are up in the archives room searching for a particular document. Maxwell says, “I might have left the document in my car.” The assistant asks, “Mr. Maxwell, is your car parked in space C8? It’s not unheard of for cars to be stolen.” Maxwell thinks carefully for a moment and then responds, “No, my car has not been stolen. It is parked in C8.”
With that example began John Turri's "Epistemic closure and folk epistemology," where he went on to add that:
The epistemic closure principle says, roughly, that if one knows that P, and one knows that if P then Q, and one infers Q, then one knows Q.
Maxwell may have been misapplying logic, when he thought carefully: he recalled that he had parked in C8, rather than D8, and so he thought that his car was in C8 (unless it had, as his assistant noted, been stolen), from which he may have concluded that it was not stolen. (But perhaps he took the low chance of his car having been stolen to be reason enough to think that it had not been stolen. And for all we know the archive's windows looked down on C8.)

Most people think that Maxwell knew that his car was parked in C8 (assuming that it had not been stolen, etc.), but not that it had not been stolen, which contradicts Closure: if Maxwell knows that his car is in C8, and he knows that if his car is in C8 then it has not been stolen (he did seem to know that because he did seem to infer, from it being in C8, that it had not been stolen), then Closure says that Maxwell did know that his car had not been stolen.

Logically, if Maxwell's car was in C8, then it had not been stolen; and the whole point of logic is that logical reasoning takes us from knowledge to knowledge. So it seems to be logical, to go from Maxwell knowing that his car was in C8, rather than D8 (which I think he did know), to Maxwell knowing that his car was in C8 (which most people think he did know), to Maxwell knowing that his car had not been taken out of C8 (which most people think he did not know).

But of course, we can see from this example why that is invalid; and so we also have this insight into why skeptical scenarios are not threats to knowledge (and also why they are). If we are BIVs then we do not have real hands, so how can we know that we have real hands but not know that we are not BIVs? If we are BIVs then we think we have real hands (which is good enough for us BIVs).

Thursday, January 18, 2018

50 meanings for "know"

To say that you know something is, basically, to say that you are certain of it; in effect, you are promising that what you say is true. Knowledge is important because we want, as a society, bodies of knowledge that can be relied upon. That is why, when cause for doubt is shown to us by skeptical scenarios, our natural reaction is to doubt that we did have knowledge; although of course, academics cannot conclude that they know nothing. At the other end of the scale, consider a boy sitting an exam, who is not sure of an answer but puts it down anyway, and it turns out to be correct: we say that he did know the answer. There are a range of uses of the word "know," and in between those two are all the sciences, and all their applications, and such varied uses of "know" give it a certain inconsistency. The analytic-philosophical analysis of "know" is therefore a cornucopia of papers. Continental philosophers may notice that you can only ever really know what you have yourself made up, however, because the paradigm case of knowledge is, as it has always been, that of a God: proposition P is known by subject S when S's justification for believing P guarantees that P is true. How close you have to get to that ideal, for what you believe to count as knowledge, depends upon the kind of knowledge that it is, the use that you are going to make of it, and so on. We pick up on the use of "know" as we learn English, and I for one have found that good claims to knowledge can be gambles, akin to promises, even though knowledge stands opposed to epistemic luck. More generally, we might disagree about the meaning of "know" without any of us being wrong. But one thing stands out: you either know something or else you do not. Justification, by contrast, comes in degrees; and that is so even though knowledge is basically justified true belief. That is because the justification required for knowledge is sufficient relevant justification. Note that if you think that you know something, because of some justification, but your belief turns out to be false, so that you do not know it, then as a rule your standard for sufficient relevant justification in similar cases will need to be revised.

Wednesday, January 17, 2018

Gettier's Smith's Job

Smith applies for a job, as does X. Smith thinks that X will get the job, and knows that X has 10 coins in his pocket, so Smith thinks that the man who gets the job will have 10 coins in his pocket. As it turns out, Smith gets the job, and also has 10 coins in his pocket, and so his italicized belief was true. Since Smith was justified in thinking that X would get the job (his new boss had told him that X would get the job) his italicized belief was also justified; but, it was not knowledge, according to Gettier.

One problem with all of that is that it is a bit obscure what exactly is going on: there was a bit of inferring going on, and as a rule we cannot rely on such things as, for example, epistemic closure: If you know that P, and also that P implies Q, then even if you infer Q, you do not necessarily know Q (there was a good example by John Turri at Certain Doubts). Still, one thing is obvious: Smith's reasons for believing the italicized belief were no part of the reasons why it was true, and so it was not knowledge.

However, because those reasons turned out not to be that good (X did not get the job), there is also a question mark over whether they really were good enough to count as justification in the sense required for knowledge (only a question mark). A statement known to be false was always a statement that could have been false (that really could, not just could theoretically). When we think of knowledge we think of statements that can be relied upon, that are justified in ways that basically guarantee their truth.

Sunday, January 14, 2018

Much Knowledge is Epistemic Luck

In a recent post (linked to here) I observed how we simply assume that we can refer directly to the things around us: we cannot know that their substances are not changing in ways that leave their properties the same, because we can only know their properties. Were their substances changing, reference to them would keep failing (assuming that reference is direct).
     And similarly, we cannot really rule out that we are Brains In Vats: all of our evidence is compatible with our brains having been harvested by aliens (in a real world where such aliens are common) and put into high-tech vats that simulate worldly experiences. While we are unlikely to have been harvested recently (as recently noted (although note that we cannot rule out as unlikely a world where are are frequently, but not too frequently, re-vatted)) it is not unlikely (by the standards of the apparent world) that there are such aliens (what is strange is that we see no aliens).
     But of course, we can and do simply assume that there are not such aliens, that we are not currently asleep in our beds and dreaming, that all of our particles are not always being switched with identical particles, and so forth. It is upon such foundations that our knowledge of the external world is built. And of course, we are not BIVs, we are not dreaming, and so on; or at least, I do assume not. And so we do have knowledge of the external world. But, because those are assumptions, such knowledge is epistemic luck.

Saturday, January 13, 2018

Something like Fake Barns

What is adequate justification for holding a belief? It depends on one's context. A true belief that was well-justified when it was formed might cease to count as knowledge within a stricter setting, such as a court-room or a laboratory. And the famous Fake Barns involve unusual contexts. And of course, one needs to be sufficiently rational. Suppose that I see a red car, in a normal road (no fake cars), for example, and so form the belief that there is a red car. But, I also have a lot of irrational beliefs that there are various objects. When there is a red car, I believe that there is, and I am unlikely to have the belief that there is a red car if there is not a red car, although I am quite likely to have some belief that there is something when there is nothing. (It is easy to think of other examples of true beliefs that might seem at first glance to be justified but which do not count as knowledge because they are held by someone who is in some way unqualified.)

Thursday, January 11, 2018

What Do Philosophers Do?

What do you know, for sure? Being sure that you have hands,
for example, could be justified ( you may be using them now,
to operate a phone or a keyboard), but you can hardly rule out
the following scenario, according to which you have no hands:

Your brain was recently harvested by aliens and you are now in a vat
experiencing a detailed simulation; your memories have been altered,
but for you "hand" still refers to things outside the vat. And out there,
those aliens have turned the real world into one enormous brain-farm.

You cannot rule that out,
but you can know that it is unlikely
that your brain was only recently harvested
and so you can, of course, know that you have hands.