Wednesday, November 08, 2006

What the Germans know. Jonny Blamey

It’s world war two. The Germans are occupying a French town and the British are going to attack at dawn, hoping to surprise the Germans. A British spy in the town finds out that the Germans know of the attack. Back at the British base the spy has this exchange with the British General:
SPY: “The Germans know we are going to attack at dawn.”
GENERAL : “Then we will call off the attack.”
ENTER PHILOSOPHER : “Why are we calling off the attack?”
GENERAL : “Because the Germans know we are going to attack.”
PHILOSOPHER: “But the German’s don’t know we are going to attack.”
SPY. “Yes they do, I heard them discussing it.”
PHILOSOPHER. “No, I mean that the Germans don’t know we are going to attack, because knowledge is factive, and we are calling off the attack. So it is not true that we are going to attack and therefore not true that the Germans know we are going to attack.”
GENERAL : “So the Germans don’t know we are going to attack?”
PHILOSOPHER : “That’s right, they don’t.”
GENERAL : “Then there is no reason to call off the attack.”
SPY (PEEVED) : “Look, if factivity is so important, I’ll rephrase it. The Germans know that we intend to attack at dawn.”
GENERAL : “Then we will call off the attack.”
PHILOSOPHER: “So we don’t intend to attack at dawn?”
GENERAL. “No.”
PHILOSOPHER. “Then the Germans don’t know that we intend to attack at dawn. Knowledge is factive, remember.”
SPY (Through gritted teeth): “Alright, you pedant, two hours ago when I was bravely spying on the Germans, I discovered that they then knew that we were then intending to attack at dawn, although they don’t know this any more.
GENERAL: “So they don’t know that we are now intending to attack at dawn?”
SPY: “I suppose not.”
GENERAL : “Then there is no need to call off the attack.”
PHILOSOPHER : “But if you don’t call off the attack, then they will know we are going to attack.”
SPY: “How about this, the German’s expect us to attack. Expectation is not factive, so they will expect us to attack whether we attack or not.”
GENERAL. “I haven’t got where I am today by underestimating the enemy. The Germans are in a state of constant readiness. They expect us to attack at all times. So of course they expect us to attack at dawn. What I want to know is whether they know we are going to attack at dawn.
PHILOSOPHER : Well, that’s up to you, if you call off the attack, then they don’t know, if you continue with the attack they do know. You see, knowledge is factive, so whether they know what we are going to do or not depends on what we decide to do.
GENERAL : “Look, I may be a military man of action, but I know a thing or two about natural science, and I know that we can’t affect the state of German intelligence in the town down there by these word games up here. Either the Germans know we are going to attack at dawn, or they don’t. Which is it?”
SPY : “They know we are going to attack.”
GENERAL : “Then we will call off the attack.”
PHILOSOPHER : “Do you see? Now they don’t know we are going to attack.”
GENERAL : “Get Out!”


PROBLEM
What do the Germans know? Does the answer to this question depend on whether the General decides to call off the attack? If so does this mean that knowledge content is external? I'm assuming that even if the British call off the attack, the Germans still know something. It is not as if they were wrong when they thought they knew the British were going to attack.

15 Comments:

Blogger Lee Walters said...

It seems that there are two candidates for what the Germans know.

1) At time t < dawn the British had an intention to attack at dawn.

This does not change regardless of whether the British attack or not. A failure to act on our intentions does not mean we never had those intentions. This seems like an unproblematic candidate for knowledge.

2) The British will attack at dawn

If the future is open, so eternalism is false and determinism is false, then it seems there is no fact of the matter to be known. Of course after the event the Germans may say that they knew the British would attack. This utterance may be true or it may not be. If it is it does not show that they knew the British would attack at the earlier time - truth may be relative to time of evaluation for instance.

If either eternalism or determinism is true then there is a fact to be known. Whether the Germans know the British will attack does indeed depend on, amongst other things, whether the British decide to attack, but that decision is fixed whether the British realize this or not. So it is not that the decision whether to attack makes the Germans' belief knowledge. Rather the Germans' state of knowledge is fixed already as is the British decision. If the British decision were different, then we would be in a different possible world and the knowledge of the Germans would be different. It is in this sense that their knowledge depends on the British decision. Fixity of the future is not fatalism and the decisions we make, whether fixed or no impact the future, fixed or no.

2:50 PM  
Anonymous jonny blamey said...

Thanks Lee, much appreciated. I was trying to block the first candidate by pointing out the failure of attempts to precisify the Spy's report. It is not good enough reason to call off the attack that the Germans know that the British intended at some point to attack at dawn, but do not know whether the British will act on this intention. This amounts to saying the Germans don't know that the British are going to attack. But they do know.
It is the second candidate that I find interesting. If there is no future fact, then it seems the Germans can't know it. But if we take it as data that they do know it, then the factivity of knowledge is challenged. I argue that they do know it because otherwise we are forced into saying that no contingent future facts are known (because there are none).
So we have 3 incompatible propositions.
1. some contingent future facts are known.
2. knowledge is factive.
3. the future is open (future contingent facts have no fixed truth value)
So lets drop 3 and accept eternalism/determinism.
The same problem seems to arise in a slightly different form.
1. Some facts about our future free actions are known by third parties.
2. Knowledge is factive.
3. It is up to us whether we perform free actions.
4. It is not up to us whether S knows that we are going to perform a free action.

I would contend that it is hard to forsake any of these four. Those who think factivity is unassailable may be in favour of dropping 1 or 4. I do not accept that factivity of knowledge is more fundamental than free action so forget dropping 3.
The thought behind 4 is that knowledge can only be affected by doubting, forgetting, misleading, confusing or brain damage. In otherwords, knowledge is a mental state. By defying someones predictions of your actions, you are not thereby affecting their knowledge, since there is no causal connection between your action and their mind. I am suggesting that the mental nature of knowledge is more fundamental than factivity. This is clear when one considers non propositional knowledge. You can stop me from knowing how to ride my bike by damaging my brain, or hypnotising me, or making me forget. But you cannot stop me from knowing how to ride my bike by switching the handel bars around so that I literally fall off when I ride it. Another eg. I'm driving to my mother in laws for lunch, I ask my wife if her mum knows we are coming. "Yes, she knows we are coming for lunch." she says. "In which case we'd better not stop for a pub lunch." I say. It wouldn't be correct for me to continue: "Because if we stopped for lunch, then she would never have known we were coming."

4:19 PM  
Blogger Lee Walters said...

The free will stuff raises separate issues so I'm going to ignore that.

RE the first candidate: you say "It is not good enough reason to call off the attack that the Germans know that the British intended at some point to attack at dawn, but do not know whether the British will act on this intention." I guess I just don't see that. If the enemy know of my plans that seems like a good reason to change them.

You go on to say that this can't be right as it conflicts with the datum that the Germans do know that the British will attack. Again, I don't see why we need be committed to this. The Germans know our plans and based on this form a justified belief about our future actions. Why say further that they know what we will do?

RE the second claim: Even if I took the knowledge ascription to be evidently correct, I guess the last thing I would conclude is some substantive metaphysical thesis like determinism or eternalism. Rather I would withdraw the knowledge ascription.

In any case I'm not sure how signing up to eternalism or determinism helps other than to solve the factivity problem. It is not as if the Germans can see into the future or have a deterministic calculator. Presumably their beliefs are based on the same evidence / they are in the same mental state regardless. There is some stuff on temporal externalism but I'm not familiar with this and am sceptical it would help.

I'm not sure how the ability knowledge case helps with the undermining of factivity given that it's not clear ability knowledge can be reduced to propositional knowledge.

7:14 PM  
Anonymous jonny blamey said...

Thanks again Lee, perhaps you don't see my point because it is not such a good point, but I'll try and explain again: The move from saying that the Germans know that we will attack, to they know we plan to attack seems to get around the problem, but fails because of the tense of "we plan to attack". I'm not too hot on grammar but planning, and intending are continuous, so we use the imperfect present. It is possible to form an intention and make a plan, but once you make a plan to x, from that point forward you are planning to x until you either actually x, or change your plans. The dilemma I am setting up is that the germans knowledge content is either
1 "At time t the British formed a plan to attack at dawn."
2 "The British are planning (present imperfect) to attack."
The problem with 1 is that it is consistent with "The British will not attack at dawn". So if the spy expresses the germans knowledge with 1, the General can then ask "But do the Germans know that we will attack at dawn." If the Spy feels for correctness he should say "The germans know we planned to attack at dawn, but do not know we will attack at dawn" then it seems that the General has no need to call off the attack, since the germans don't know of the attack. To make this more plausible, suppose the British had made many plans, they had planned at some point to attack everyday. But they had abandoned all these plans in favour of the one plan, to attack at dawn. So the General is only concerned if the Germans know that they are planning to attack at dawn.
The other horn, 2, is what I'm really interested in and need help with. Planning to attack is a continuum. If the Germans believe the British are planning to attack, and the British are planning to attack up until time t, but then change their plans, then what are we to make of factivity? Do the Germans know that p until time t, and falsely believe that p there after? This would seem straightforwardly the best way of describing the case were it not for two things, A. It seems difficult to say this naturally, because it seems that a mental attitude can't change from knowing to believing without there being a mental change. B. Under many accounts of knowledge, if the belief could be false after time t, then it wasn't sufficiently well evidenced to be knowledge before time t.
I admit that in the example, my blocking of 1, the British at time t < dawn planned to attack at dawn, is weak; but this could be fixed by changing the example. Eg: "Mum knows I am walking to Salisbury" I am walking to Salisbury, but half way I give up and go home. When I give up and go home, what happens to Mum's knowledge?

10:14 PM  
Blogger Lee Walters said...

Johnny,

thanks for the comments. Feel free to ignore this if I'm still missing the point.

You think the problem with 1 is that it is consistent with no attack and that the Spy should only say something like "The germans know we planned to attack at dawn, but do not know we will attack at dawn". I agree but note that 2 is also consistent with no attack. But surely this still gives the General a reason to call off the attack. The Germans don't know there will be an attack but they know of the plan and we can reasonable believe are readying themselves for the attack, which they believe justifiably will happen. In this case I suggest that knowledge of the plan gives a reason to call off the attack.

In the modified example where there have been many plans it is still the case that if the Germans know of the plan, and didn’t know of the other plans, there is a reason to call off the attack as in the last case. If the Germans knew of all the unacted upon plans, then it is like the boy who cried wolf. We still have a reason to respond to his cries but this may be overrriden. Similarly, the fact that the Germans are aware of this plan gives some reason to call off the attack but perhaps not a sufficient reason. But this seems to carry over to 2 also. The Germans know we are planning to attack, but they knew we were yesterday and the day before etc and we did not. What the general needs to know is are the Germans readying themselves for an attack. In the cases where there is only one plan, the General has good reason to believe the Germans are readying themselves for the attack, since they know about the plan/planning and this is a good reason for the Germans to ready themselves.

You are of course right that planning is a continuum, so if the Germans know we are planning, we stop planning and knowledge is factive that the Germans cease to know we are planning. You don’t like this simple account for the two reasons you give. Here are my comments, but if it isn’t already apparent that I don’t know any epistemology it soon will be.

You say there cannot be a change in a mental attitude without there being mental change. And I presume you are assuming that a change in the facts external to the Germans’ heads is not a mental change (of course it is it’s a change in the British’ mental states, but that’s not relevant I presume). By why think this last sentence? Presumably knowledge as a mental state is an externalist thesis, so change in the extra-head facts can change mental facts? Is there some particular problem that I am insensitive to in this case? If it is not an externalist thesis then it seems implasuible that knowledge is a mental state, rather than a mental state + true compound or similar.

Your second reason for rejecting the simple story above is that is a belief could be false after time t then it wasn’t sufficiently well evidenced to count as knowledge in the first place. But this way scepticism lies! I take it the vast majority of our knowledge that p is consistent with ~p and that this in tself is not sufficient to rob us of our knowledge. Similarly the fact that we would believe p even if ~p in similar circumstances does not undermine our knowledge, contra Nozick. If I see a barn and form the belief that there is a barn in front or me, this seems like an excellent route to knowledge. However, as it happens if there were no barn in front of me, God would produce an image of such barn-like quality that I would form the same, but this time false belief. Does this potential false belief rob me of my knowledge. I don’t see why but you may have different judgements. More controversially, I am not convinced that if I look at the true barn in fake-barn county I do not have knowledge. I know these are not temporal examples, but the same applies I think.

11:34 AM  
Anonymous jonny said...

Thanks for sticking with this Lee, you are starting to say things which are consistent with the point I am trying to make with this, which I admit is subtle. The datum I am taking from the example is that when the Spy says : "the germans know p" he is saying something important and true to the general. The question is what? If the philosopher is right, and knowledge is a propositional attitude to a true proposition, it seems problematic. Where my point is weak is if you can simply say that the proposition p has content "the british plan at t to attack at dawn" and this is enough for the general to change his plans. I want to ignore this solution, since I think that it can be blocked by changing the example. What I am trying to extract is that, as you say "What the general needs to know is are the Germans readying themselves for an attack", but that he needs to know more than this, because the Germans may diligently be readying themselves for an attack without knowing that there will be an attack. I'm trying to get at the fact that saying that the germans know that p is principally to convey information about the germans dispositions to attack, and only parasitically about p. Philosophers have put too much emphasis on the first person case, so this ordering of importance is neglected. If I say "I know p", or wonder "do I know that p" this is in part an inquiry into p, so the significance of the factivity of knowledge seems greater than it is. Nozick, Lewis and others jump across "worlds" as if this was a quite ordinary way to talk, but I'm jumping across times in the actual world. So to take my walking example again, me and Jo are walking to Salisbury. I say to Jo, "Mum knows that we are walking to Salisbury." What I principally am trying to convey to Jo is that Mum will act and reason in ways that are consistent with the fact that me and Jo are walking to Salisbury. I am not telling him that we are walking to Salisbury. My argument for this is the rather weak one that if we were to give up walking to Salisbury, Jo wouldn't say "You're Mum didn't know we were walking to Salisbury." Nor "Your Mum has stopped knowing that we are walking to Salibury." But more naturally, "Your Mum still thinks we are walking to Salisbury." The point is subtle because I am not outright denying factivity, I'm just trying to point out that factivity is less important than the psychological factors. I need to do this because philosophers will often thwart attempts to talk about the psychological aspects of knowledge attributions by insisting on the factivity of knowledge being an entailment relation between knowledge attributions and truth. So in the Germans example I was trying to get a kind of liar paradox going where the Spy wants to say that the Germans know that p, but by saying this he makes it the case that p is false. Under this kind of strain, the factivity of knowledge, I hope, gives way, rather than the more important psychological data about the Germans. If you insist on factivity winning over psychology, then I hope to force either i) skepticism, which you point out is rebarbitive ii) a mis-translation, in other words, if you just say the germans think we are going to attack, or expect, or falsely believe, but do not know, you are missing valuable information about the situation.

12:35 PM  
Anonymous Rob_S said...

"...if we were to give up walking to Salisbury, Jo wouldn't say "You're Mum didn't know we were walking to Salisbury." Nor "Your Mum has stopped knowing that we are walking to Salibury." But more naturally, "Your Mum still thinks we are walking to Salisbury.""

But mum did (past tense) know you were walking to Salisbury, so of course Jo won't deny that. Indeed, it could be true that you were walking to Salisbury even if you had never started walking. Cf. "How are you getting there tomorrow?" "I was walking but now I've decided to drive."

The second thing Jo doesn't say, "Your mum has stopped knowing..." is certainly strange but I can't see what that really establishes. If the Royal Courts of Justice were knocked down, it would be odd to say "KCL has stopped being near the Royal Courts of Justice." It would mislocate the activity, or some such.

And the thing Jo does say, "Your mum still thinks..." seems to explain mum's behaviour pretty effectively, without knowledge being invoked. Isn't this what you want to deny?

10:54 AM  
Anonymous jonny blamey said...

Thanks for your comments Rob. There are some basic grammatical issues that are confusing me. My issue is this. There is such a thing (I claim) as a conclusive inductive argument, or conclusive evidence. If S has conclusive evidence that p, then S knows that p. But conclusive evidence is fallible. Sometimes people have conclusive evidence that p and yet p is false. In which case they do not know that p. So conclusive evidence is sufficient to know that p, without entailing that p. While it is clear that ~p entails that S knows that p is false, it is not so clear that S knows that p entails that p is true. Otherwise you can bootstrap an inductive argument into a deductive argument like this: I have conclusive evidence for p, therefore I know that p, S knows that p entails p, therefore p. Now I have a deductive argument for p from purely inductive grounds. One way to avoid this bootstrapping is to deny that conclusive evidence is sufficient for knowledge, but this is too sceptical. The other way I am trying out is to deny that S knows that p entails that p. This is not an outright denial of factivity, since S knows that p can still be conclusive evidence that p, and ~p can still be conclusive evidence that S does not know p. So I'm trying to use these present imperfect tenses to show that if p can change from true to false over time, then it shows up in linguistic behaviour that the inference from s knows that p to p is not that of entailment. So "Mum knows I am walking to Salisbury" doesn't entail that I am walking to Salisbury. The reason being that I can assert sincerely that Mum knows I am walking to Salisbury, without asserting that I am walking to Salisbury.
The grammatical confusion comes from a possible implicit intentionality of future tense and present imperfect. "We are going to attack" doesn't entail that we are going to attack, though if we don't attack "we were going to attack" still seems to be true.
It is undeniable that conclusive evidence works in this way. We have conclusive evidence that p doesn't entail that p, though if not p "we had conclusive evidence that p" still seems to be true. It is more controversial for knowledge, but still plausible. EG. "We all knew then that John Smith was going to be the next Prime minister; and if it hadn't been for his untimely death, he would have been."
So I'm liking your "KCL has stopped being near the royal courts of justice". Suppose Sid knew that Dave worked at the royal courts of justice. Sid would have conclusive evidence that Dave worked near KCL. Sid knows that Dave works near KCL. When the courts relocate, his evidence doesn't change, but it is no longer conclusive. He still thinks dave works near KCL. It just seems strange to say that part of the relocation is a change in Sids knowledge.

12:09 PM  
Anonymous Rob_s said...

Right, I see what you are getting at. It's interesting how pervasive the grammatical ambiguity seems to be. Consider this from your previous comment:

""We are going to attack" doesn't entail that we are going to attack, though if we don't attack "we were going to attack" still seems to be true."

But I could just say that it does entail we are going to attack. I mean, look at the form of the claim: ""p" doesn't entail that p". In logic, this would be considered a mistake.

What's needed ideally I think is an example where one person can properly assert both "S knows that p" and "not-p", without there being an easy response available, to the effect that p has two different senses here (e.g. the first one is about an intention, the second about a real future event). I can't think of any good examples, although I note in passing that the book in front of me, Silence of the Lambs, says on the back "Can his genius help trap the killer that knows that beauty is only skin deep?" Here I think the killer is not supposed to be in touch with a truth about beauty -- rather he (Jame Gumb if you know the book) is fatally mixed up about it. But then it might easily be said that this piece of blurb misuses the word "knows".

12:40 PM  
Anonymous jonny blamey said...

There is little hope of an example of "S knows that p but not p" since, even if I am right, not p is conclusive evidence that S does not know that p. Much more abundant are examples of "S knew that p, but p is not now true". These can be explained by claiming that the two instances of p refer to different propositions that are timelessly true/false. The propositions are then time indexed. So "S knows that I am here (t1), but I am not here (t2)" is fine. Where it gets less easy is to index a present imperfect tense to a time and get a single timeless proposition. So "We are going to attack the Germans at Dawn (t1) but we are not going to attack the Germans at dawn. (t2)" It is confusing as to what the indexes refer to, since they do not refer to dawn. I reject the idea that the index refers to the time of an intention, this would be "we intended to attack the germans at Dawn at t1, but we did not intend to attack the Germans at t2." this is because the same problem arises in non intentional situations. For example "The fire was going to spread to the village but luckily it started raining." This is implies "The fire was going to spread to the village (t1) and the fire was not going to spread to the village (t2)"
My solution to explain the difference is to say that at t(1) there was conclusive evidence that the fire would spread to the village, and at t(2) there was not. Since the relationship between conclusive evidence for p and p is not one of entailment, and it is fallible, this is not a contradiction. If conclusive evidence is sufficient for knowledge, then I can say truthly "Jack knew (t1) the fire was going to spread to the village, but (t2) the fire wasn't going to spread to the village."
This will, if fleshed out, give an account of counterfactuals and subjunctive conditionals. So "If it hadn't rained, the fire would have spread to the village" is true if and only if, before it rained, deleting the assumption that it was going to rain, there would have been conclusive evidence that the fire was going to spread to the village.

3:32 PM  
Anonymous jonny blamey said...

By the way, "knows that beauty is only skin deep" yes, haha,
This would actually fit my account well, since Hannibal has conclusive evidence that beauty is only skin deep.

3:38 PM  
Anonymous Rob_s said...

Don’t know if I totally get this, but it looks neat. If I do understand, my concern is that the fire really was going to spread to the village. It wasn’t just that we had conclusive evidence that it was. Similarly in the WWII example, the English really were going to attack.

We could have had conclusive evidence for both of those things, but that wouldn’t automatically let us say that we knew them. For example, it could transpire that the English had never even formed an intention to attack, and that the fire was in fact following a different trajectory all along. If we discovered this, we would say, “They didn’t know p after all.“ Why the difference?

5:18 PM  
Anonymous jonnyblamee said...

Yes, it gets very metaphysical. There is a lot of strain on "conclusive evidence". I think you a suggesting that something like this would make sense: "We (the germans) had conclusive evidence that the english were going to attack, but (it later transpired) they never were going to attack", Which I agree clearly makes sense. But this is down to the plausibility that the germans concluded on their evidence that the English had intended to attack, but the English never had any such intention. So switch to the non intentional case. "We had conclusive evidence that the fire was going to reach the village. The rain then came, defeating our evidence. But really, the fire was never going to reach the village." This is less obviously meaningful, but its best interpretation is that the fire wouldn't have reached the village even if the rain hadn't come, because say, there was a big ditch between the fire and the village. If we have a view of the truth of counterfactuals that is linked to evidence and assumptions, then this will be more of the same. We can now say that it is true that the fire was going to reach the village, but there was a ditch in the way. The German case could probably be explained in this way too, but the German's evidence for the British attack isn't explicit, because we don't know what it is.

7:24 PM  
Anonymous Rob_s said...

Hmm. I'm a bit mystified by counterfactuals so not sure what to say, but it seems to me there is a difference of kind between your example of "The fire was going to reach the village but there was a ditch in the way" and "The fire was going to reach the village but it was going in the wrong direction." And between "The English were going to attack but they changed their minds" and "The English were going to attack but the idea never occurred to them." I am wondering how well a conclusive evidence account could deal with this distinction. But probably a lot more background would be needed to address this.

11:42 AM  
Anonymous jonny blamey said...

I'm mystified too now. 1 "The English were going to attack at dawn, but the idea never occured them" just seems wrong, whereas 2 "The English would have attacked at dawn if the idea had occured to them" seems fine.
The reason is that given that the idea never occured to the English to attack, then it seems false that they were going to attack. Whereas if you change the second part to "but they changed their minds", then 1 and 2 seem to be interchangeable.
A general conclusive evidence solution is that with "X was going to Y but Z", then Z must be a defeater for conclusive evidence that X will Y, whereas with "X would have Y if Z" then Z can be an added assumption as well as a defeater.
So you can't say "the fire was going to consume the village, but there was no fire." But you can say "If there had been a fire it would have consumed the village".
If this is right, then there could be complicated cases where eg. the germans could truthfully say "The Brits were going to attack at dawn but had no intention of doing so", although they will be rare. The only plausible eg I can think of is "He was going to become head of department, but he just didn't want the post" Where "he was going to become head of dept" is true because, everyone expected him to want the post, and knew that if he wanted it he would have got it. What later transpired was that he had no intention of becoming head of dept. This counts as a defeater, because the speaker just assumed that anyone would want to become head of department. I'm thinking of more egs now... He was just about to score a goal, but it turned out that that wasn't what he was trying to do.

12:47 PM  

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