On Philosophy

November 30, 2006

Historical Causes

Filed under: General Philosophy — Peter @ 12:53 am

Let us say that we are contemplating some future event. Obviously there are some current factors that we can single out as causes of that event. Are there also past events that we can pick out as causes, or are we limited strictly to talking about what currently exists when we discuss causation?*

The answer is yes and no. Specifically it depends on how we wish to deal with causation. It is generally accepted that causation can be dealt with through counterfactuals; usually of the form: if it is the case that without some factor, X, Y wouldn’t occur then we say that X is a cause of Y. Of course things can get a little more complicated when several causes are coming together to produce some result (a discussion of which is here), but such difficulties have no bearing on our discussion here. And when we investigate causation through counterfactuals we also assume that everything else is held constant, and this is where the difficulty with historical causes arises. One way to interpret talk of historical causes is to assume that only that past moment in time is altered in our counterfactual considerations, with subsequent moments remaining unchanged. Obviously such an interpretation would mean that the historical events could never be considered causes, since the current state of affairs wouldn’t be affected, and thus the future event, Y would not be affected either. Or we can understand talk of historical causes as not holding the rest of the past constant. Instead we can assume that what we mean by our counterfactual claim is that the event in question and the events that resulted from it are allowed to change. In that case some historical events can legitimately be said to be causes, since a change in that historical event would result in a sequence of changes, possibly including a change in the future event under consideration.

I think the second interpretation is often the better one, since we usually accept that if A causes B, and B causes C then A can be said to be a cause of C. What is important to note though is that a historical event can only be said to be a cause of some future event if it is part of a causal chain that includes some present events. In general we can say that if an event at time t1 is to be a cause of an event at t3, and if t2 is between t1 and t3, then the event at t1 must be a cause of some events at t2. This conclusion is not a metaphysical thesis about the nature of causation, certainly I can imagine universes with laws that allow an event at one time to cause effects at future times without intermediate effects. However, our world is not like this, as far as we can tell future moments depend exclusively on the immediately previous moment.

And this makes talking about historical causes a bit tricky. Specifically, when wondering whether historical causes are epiphenomenal. As I pointed about above there is a valid way of talking about them in which they aren’t, but that is because they take part in a chain of events. So precisely speaking it is the causal chain that is not epiphenomenal, not the historical events themselves. If we were considering the historical events alone, outside of the causal chain, then we would have to say that they are epiphenomenal. And this is relevant to a particular kind of externalism, that identifies mental content with certain historical factors resulted in adaptations that allowed the creature to represent the world. Certainly the causal chain including these factors is not epiphenomenal, but the historical factors by themselves are. We can imagine a spontaneously generated duplicate of some individual, and since it would act in the same way as the original, we can conclude the historical factors by themselves have no effect. Properly speaking then it is only the current state of the individual that is a cause, historical factors can only said to be a cause in virtue of their effects upon this current state. And thus an externalism that ties representation to historical factors is still epiphenomenal, since those historical factors only have an effect in virtue of current properties.

(This is a more detailed discussion of one part of my response to Dretske’s externalism, here.)

* For simplicities sake I have framed this discussion in the “current tense”, i.e. looking at the causes of a future event from some present moment, with consideration given to past events. It is trivial to generalize this to talk about effect at some moment, causes in the immediately previous moment, with consideration given to possible causes at previous moments.


November 29, 2006

What Is Truth? (2)

Filed under: General Philosophy — Peter @ 12:03 am

What if truth was merely a linguistic property? Certainly it seems like this might be the case, after all, the only things it makes sense to predicate truth of are sentences in some language. Of course this doesn’t explain what truth is, it simply puts us on the path to an answer; we still have to say why one sentence is true while another is false.

The first idea that springs into everyone’s mind is to appeal to accuracy. That is we want to say that a sentence is true if it accurately portrays its objects (without error). But then we must define what accuracy consists of, and we might be tempted to think that it is some kind of correspondence, between the way things actually are and the propositions expressed by the sentence. This is essentially the correspondence theory of truth, and its problems are well known, specifically it is hard to say what certain true statements, like true mathematical statements, could correspond to.

Another possibility is to define accuracy in terms of other people, specifically to claim that an accurate sentence is one that all people would agree with (or a majority of people). This certainly has some appeal; we no longer have to worry about how to define the connection between true statements and how the world really is, as we assume that if everyone agrees to the statement there must be something that causes this agreement. And such a definition is not inconsistent, but unfortunately it doesn’t capture what we mean by truth either. I think we can all agree that there are many true statements that are true independently of what people believe (for example: “the earth orbits the sun”). A definition that relies exclusively on people cannot capture this property of truth.

Let me propose a third possibility then, that what we mean when we say that a sentence is true is that, if the sentence is correctly understood, everything that the listener has experienced, and can in principle experience, will agree with it. This definition of course leans upon our ability to understand the meaning of sentences. Although defining what meaning is, and how we come to grasp it, may be problematic I do not see any reason to think that understanding this ability will rely on truth (and thus this definition isn’t circular). This definition certainly seems acceptable for the “normal” cases (although most theories of truth are). For example, if I claim that “‘some cats are white’ is true” then I am asserting that one could possibly encounter a white cat. If one couldn’t encounter a white cat then that would mean that there were no white cats, which would mean that I was incorrect in asserting “‘some cats are white’ is true”, meaning that the statement is false, which would really be the case. Now we might worry that this definition relies too heavily on our senses, and that “truth” might then differ for a blind man. This is really not the case, because the experiences we are referring to are experiences possible in principle, meaning that the blind man could use instruments, or even a reliable reporter of events, to experience the existence of a white cat; he doesn’t have to see it.

So let me turn to the cases that are typically problematic, specifically the cases of mathematical truths and recursive truth claims (i.e. sentences of the form “‘X is true’ is true”). To determine how this definition of truth handles cases of mathematical truth we must explicate how one can experience a mathematical statement. I am not a mathematical realist; I don’t think that formula and numbers are the kinds of things that can be experienced. I do think, however, that we can experience the proof of a statement in mathematics (for example, by seeing that proof written down, or by thinking it up). Thus, if X is some mathematical assertion, I think that to say “X is true” is really to mean “‘X can be proven’ is true”. And this statement is not problematic, because it either is or is not the case that we can experience a valid proof of X from some axiom set, in some logical system (I assume that those constraints are determined by context). Finally then we come to the case of recursive truth claims. To see how the definition of truth presented here handles these we must unpack them. “‘X is true’ is true” thus becomes: “In principle we can experience that ‘X is true’”, which becomes “In principle we can experience that ‘In principle we can experience X’”. This means that the initial claim is true if we can experience experiencing X, which is only possible if we can experience X. And thus the statement means the same thing as “X is true”, as it should. So neither mathematical truth nor recursive truth claims give this definition of truth problems, which is surely to its credit.

To conclude I would like to make two observations about this definition of truth. The first is that although this definition has some similarities to verificationism it is not a version of that school of thought because it deals with what can in principle be experienced versus what can actually be experienced, which makes a world of difference (for example, a verificationist would be unable to make claims about things that they did not have the instruments to detect). The second is that given this definition of truth there are, strictly speaking, some statements that are neither true nor false. Specifically, statements about objects that are, even in principle, unobservable have this property (for example “undetectable pink unicorns exist” is neither true nor false). However, because the objects these sentences are about are undetectable they must also be unable to have a causal effect on the world (see here), and thus our inability to speak about them is not entirely unexpected, since in many ways such objects are nonsense, and a sentence that can’t be understood isn’t true or false either.

November 28, 2006

Input And Experience

Filed under: Mind — Peter @ 1:12 am

It would be able to be nice to have a definition of what exactly constitutes an experience, preferably without reference to consciousness. Now I admit that, properly speaking, experiences are only found in conscious systems. So what we really want to define is a proto-experience, something that when had by a conscious system we would call an experience. Initially we might simply think that input in general is what I am calling proto-experiences. Input into an unconscious system, like a thermostat, is simply data, while input into a conscious system is an experience. Unfortunately things aren’t so simple. Consider, for example, the phenomenon of blind sight. A patient with blind sight has lost the ability to have the experience of vision at least for part of their visual field. Consciously they are blind in that area, but the information is still reaching their mind; when guessing (randomly, or so they think) they demonstrate that they have, unconsciously, some information about what going on in that region, as they “guess” spectacularly well. Blind sight then is an example of input into a conscious system that is not part of an experience.

Obviously in blind sight the input is only goes to the unconscious mind. But this does not answer our question, about what experience is. We might be tempted to say that it is input into the conscious mind, but the unconscious is part of the same system as the conscious mind, so what makes one kind of input experience and the other not? The key, I think, is how the information contained in the input is made available to the mind, and, more importantly, future mental states.

Previously I have put forward the thesis that consciousness arises from a kind of circular or reflexive structure. In a conscious system the information that makes up the conscious mental state at one moment is incorporated into future conscious states (I won’t go into all the details again here). What is relevant to our discussion about experiences is that it is this circularity which allows the contents of the conscious mind at one moment to be reflected upon in later moments. Thus it is my contention that what differentiates an experience from mere input is that the contents of the experience are incorporated into future mental states in the right way, while mere input goes directly to behavior.

Reflexes are a good example of this. The input that causes us to, for example, pull back from something hot does not immediately become part of the conscious mind. We react before we are aware of why we are reacting. And thus the input that caused us to pull away is effectively unconscious and nor part of experience, as it immediately causes us to pull away, and is not incorporated into the mind in a way that allows it to be reflected upon. Of course that input does become part of an experience after the reflex has occurred, but until it does, while the reflex is occurring, it is unconscious, simply input.

Now I did mention that the input had to be incorporated into a reflexive structure in the “right way”, and that deserves some clarification. The “right way” for a particular kind of input, say sight, is that when that input is processed, it is treated as sight. For example, if a system has visual input from a tree, and if that visual input is to be part of experience, then any thoughts or responses that the system generates as part of the circular process that defines experience must be about it as visual, not as a hunch, or smell, ect. What the difference might be in simple creatures is hard to imagine, but for people it is clear, it must be thought about, in every way, as vision (it must feel like vision). This is why the visual input in patients with blind sight is not a visual experience, even when they are correctly guessing about the contents of the region they cannot consciously see; that information is incorporated into their experience as a random guess, and not as visual input. When they reflect upon it they don’t think of it as sight, they think of it as a guess. Thus they have the experience of guessing, but not the experience of seeing, even if their guess and the visual input contained the same information.

Below is a diagram that I hope clarifies things at least a little bit:
There are two things that I would like to mention about this diagram. One is that the region I have labeled as “working memory” really stands for the current content of our experiences, which are in some way incorporated into future experiences. I have labeled it “working memory” because it is possible that this information is stored in short-term memory, although this is not necessarily the case. I would also like to note that the last section, showing how an input can be part of a conscious system but not part of experience, is not the only way this could happen, it simply illustrates one of the possibilities. It could, for example, go through some route that incorporates it into the region I have labeled “working memory”, but not as an input (this would be the case with blind sight).

This post acts as a complement to this one, about the first person perspective, in which I left unanswered the question of what a proto-experience was. Together they lead to the conclusion that if a system can be said to have proto-experiences, and those proto-experiences support a first person perspective, then the system is conscious.

November 27, 2006

The A Priori

Filed under: General Philosophy — Peter @ 1:35 am

When we claim that something is a priori we are claiming that it can be known to be true independently of experience. Of course we may be mistaken in judging that something is a priori (Kant famously thought that we could know space to be Euclidean a priori), but it seems self evident that there are at least some simple truths, such as 5 = 5, or “all bachelors are unmarried” that simply must be a priori.

Let us first turn then to the logical truths (and thus mathematical truths), which can supposedly be known a priori. We might reason that since there is only one way to correctly reason logically then this way could be discovered without reference to the external world, since the other possibilities would be in some way incoherent. However, this conclusion rests on a flawed premise, namely that there is only one coherent way to reason logically. Numerous other logical systems have been developed in recent years, sometimes proving useful and sometimes being nothing more than curiosities. Even if we were to start with the same set of axioms, in some systems we would be able to deduce that 5 = 5, in some that 5 = 4, in some both, and in some neither. How then can we claim that 5 = 5 can be known a priori? We might think that we could relativize our claim to the logical system we deduced it from (i.e. 5 = 5 under classical logic), but this isn’t real progress because every conclusion can be deduced under some logical system (some systems allow one to deduce all possible statements). So we would still be forced to conclude that every statement could be known a priori, which is unacceptable. What we really want is some way to pick out, in an a priori fashion, which logical system is the “right” one, and thus be able to discard the conclusions derived from the others. Unfortunately the way we decide which logical system is “right” is by observing which one most closely reflects the way truth is preserved in our experience. For example, we know that a person can’t be in two places at once, so any logical system that allowed us to deduce that I could both be in the store and not be in the store at the same time (from some basic set of axioms about objects and locations) would be a bad one. But we can’t make this move without some appeal to experience, or common sense derived from that experience. And thus to say that some statements are a priori because they are logically necessary is to say that every statement can is a priori. Thus if the a priori is to be a meaningful category statements cannot be said to be a priori because of their logical status.

So then, how else can we pick out what is a priori? Another possibility is that whatever can be known to be true based solely on the definitions of words (or the meaning of words) is an a priori truth. Now obviously there might be some issues with assuming that the definitions of words can be known outside of experience, but let us just assume for a moment that they can. The problem with this is that either some of the statements that are thought to be a priori under this criterion will be false or the words aren’t guaranteed to actually refer to existing objects. To see why consider a person who knows the meaning of every word shortly after the discovery of the neutrino. When neutrinos were discovered it was thought that they couldn’t interact with matter, so the definition of a neutrino was something along the lines of “a particle produced by reactions: … that does not interact with matter”. And so such a person could know sentences like “all bachelors are unmarried” and “neutrinos don’t interact with matter” to be true a priori. But neutrinos do interact with matter, it just happens very rarely. And thus at least some of the things this person knows to be true a priori are actually false. Or if we don’t want to say that they are false we could say that their use of “neutrino” didn’t refer to real neutrinos, and hence the sentence they thought to be true a priori was really meaningless. Both responses may be acceptable, the problem really is that the person can’t pick out which words don’t refer to real objects, or which sentences are false, a priori. Again, this would make the a priori essentially useless, because even if we can put forward some statement as something that can be known a priori we have no guarantee that the statement is either true or meaningful.

There is perhaps one exception to this: sentences dealing with words that refer to things constructed by the words themselves, such as “bachelor”. Unlike neutrons there is nothing more to being a bachelor than what we define it as. Even with this exception in mind, we can conclude from the above arguments that claiming something to be a priori is to say little. It might have some force when speaking about things we have created through our definitions, but there is no need to investigate such things, and to show that some claim about them was a priori would be to tell us only what we already knew. Of course, what comes to mind when I think of claims that are put forward as a priori is bad metaphysics. There are some philosophers who, though some conceptual analysis, will produce claims that they claim are a priori, and thus supposedly true and unquestionable. But as we have just shown these claims have little force, and can be safely ignored (since their subjects are never things that we have constructed, but rather things such as consciousness, causation, nature, ect).

November 26, 2006

Two Causal Theories of Names

Filed under: Language — Peter @ 12:00 am

If proper names are to be thought of as rigid designators we can’t explain how our use of a name comes to refer to a person by appeal to definitions alone (of the kind: “A” is the person who ….), as that would make proper names simply abbreviations of definite descriptions. We do need some account though; if rigid designators are to be anything more than an intellectual curiosity it must be shown that our use of proper names comes about in such a way that we can legitimately say that the name refers rigidly to some person. To fill this gap Kripke introduced the causal theory of names. In its original version Kripke proposed that a name became “attached” to some object through an initial naming event, and that if we come to know that name through a causal sequence of the right kind then when we use the name we are using it as a rigid designator for the thing that was initially named.

Let us put aside the problematic nature of the right kind of causal chain.* Even if we assume that such chains exist for proper names there are still problems with this theory. Let us pretend that the baby who was named Napoleon was replaced with another baby, who had been named something else, who then went on to do all the things that we think that Napoleon did. It would seem that when we speak about Napoleon we are really speaking about the imposter, and that when we use the name “Napoleon” we are making reference to the imposter. But this contradicts the causal theory of names because according to Kripke when we speak of Napoleon we are making reference to the baby who was named Napoleon, and not the imposter. Although it might be possible for some to accept this consequence it certainly seems unintuitive. And more importantly it means that we can have perfectly understandable conversations about the man who we mistakenly think is Napoleon, communicate information about the imposter, ect, all while referencing someone completely different. And if we accept this we are accepting that the reference of rigid designators makes no difference. And if that is the case there is no point in discussing them, or appealing to them, since they don’t reflect actual the actual use of proper names, exactly the problem Kripke was trying to avoid.

To solve this problem Garth Evans has come up with a second version of the causal theory of names. He proposes that the person who a rigid designator refers to is the source of the majority of our information that we have associated with the name. Thus “Napoleon” refers to the person who is the source of most of the information we associate with the name Napoleon. This causal theory of names thus resolves the problem of imposters, since if the imposter replaced the baby named Napoleon at birth then when we use the name Napoleon we are referring to the imposter, since it is he who is the source of most of the information we associated with Napoleon.

But let us pretend that I am talking to you, and that I have told you that the baby named Napoleon was replaced shortly after birth. If I then tell you that Napoleon went on to become a flower salesman you know exactly whom I am referring to, the man who was originally named Napoleon and then replaced. But how is this possible? If Evans’ theory is correct then whenever I use the name Napoleon as a rigid designator it refers to the imposter. But here I am clearly using it to refer to someone else. Now some might contend that my use of it in that context was not as a rigid designator, but it is hard to see why not. We can’t appeal to the causal theory itself; that would be begging the question. And, aside from the causal theory, it seems just like every other use of name; if we can legitimately claim that it isn’t a rigid designator than we can legitimately claim that names are never rigid designators.

Obviously then context at least partially determines whom we are referring to with the use of a name. We might then to be tempted to attempt to construct some kind of hybrid theory, in which we combine context with a causal chain, but I don’t think this can be done without making names just a kind of definite description. This is because context can be best captured as some set of properties that hold for the person being referred to (i.e. the person originally named Napoleon, the person that appears to be drinking a martini to my friend, ect). And if these properties are involved with reference then what we have are definite descriptions, not rigid designators.

And so I must conclude that proper names are not rigid designators, and thus that rigid designators, if they do exist, are not part of language.

Side note: Another example that shows how context plays in important role in whom we are referring to when we use a name is when we know two people with the same name. In such a case we are able to refer successfully to both of them, usually without confusion, a fact that cannot be explained by naming events, or information about them, alone.

* It is extremely hard to describe what constitutes a valid link in such a chain. We might initially think that it has something to do with a speaker who uses the name as a rigid designator passing it on to another person in the right way. But this seems to be a flawed definition since the name might be passed on in an indirect fashion, though a book, or electronic medium, in code, ect. What if in transmission of the name there is an error, changing one letter to another, but then later there is a second error that changes the letter back to the way it originally was. Is this an invalid causal chain (it certainly seems it should be, since the name communicated isn’t completely dependant on the original name, but instead depends also on the nature of the error)? But if it isn’t valid why does a transmission of the name containing a reversed error and a transmission with no errors have the same end result (results in the same behavior, same use, ect)? Doesn’t this show that our use of the name is the same even if it isn’t a rigid designator, which is the exact opposite of what the causal theory of names was supposed to show?

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