Showing posts with label inference. Show all posts
Showing posts with label inference. Show all posts

Sunday, September 1, 2013

Truth, knowledge, skepticism, and stuff…



A standard philosophical definition of knowledge goes as follows:

(I know A) <=> (I have a justified belief that A) and (A is true)

As I write this essay, I’m in the middle of reading Robert Nozick’s discussion of knowledge and skepticism in Philosophical Explanations.  Nozick uses a very specific concept of “truth tracking” which leads to some very interesting results, but is essentially (it seems to me) just a particular approach to defining justification, one that leads to a coherent (I think), but sometimes quite peculiar conception of knowledge.  I find myself working around a rather different rejection of philosophical skepticism.  What follow are musings, not intended to represent a complete expression of a developed idea.

If some particular skeptical scenario (SK: SK => not-A) were true, then A would be false, and I would not know A.  However, A, so not-SK, and I do know A.  The skeptic’s objection fails, because SK is not true.

Truth is outside my direct experience.  It is not something I have direct access to.  To use Dewey’s language from Experience and Nature, it is not something I “have directly”.  All that I have directly is justification (evidence, inference rules, trusted sources, etc.)  There is no way to operationalize truth; I can only operationalize justification.  One reason that theories of knowledge remain so problematic is that knowledge, vs. justification and belief, has exactly zero influence on our behavior at time t = now().  We try to justify our beliefs, and to act on justified beliefs.  Later, we may come to believe that our prior beliefs were not (properly) justified, i.e., were false.  But at any given moment (outside of certain contexts of philosophical inquiry) the question, “Are my beliefs true, or merely justified?” is never a useful one.  The question, “Is this belief justified?”, however, is (always?) an important one.  Operationally, the question of “truth” always devolves to:  from perspective B (perhaps a later one), do the beliefs held to be justified from perspective A still appear justified?

There is no way to operationalize (general, philosophical) skepticism at all.  Skepticism places all logical possibilities on an equal footing.  All available evidence is discounted, and there is no way to distinguish one possibility from another, to prefer one over the other.  Skepticism cannot give any positive plan of action.

Philosophical skepticism of the sort I am referring to (what Hume referred to as Pyrrhonism) must not be confused with a critical evaluation of our methods of justification.  Critical evaluation of our methods of justification is completely operational and is critical to ensuring that they track truth as closely as possible.

P.S.  Nozick, I think, expresses an insight similar to mine above about truth and experience when he says (p. 232 in my paperback copy) “We have said that knowledge is a real connection of belief to the world, [which we call] tracking, and… this view is external to the viewpoint of the knower, as compared to traditional treatments, [though] it does treat the method he uses [to track truth] from the inside, to the extent it is guided by internal cues and appearances.”

P.P.S.  Anticipating certain gleeful but misguided reactions to my rejection of “skepticism”, I want to point out a deviation between a common vernacular use of the word “skeptical” and philosophical skepticism, to wit, the phrase: “Skeptical about God.”  Disbelief in God (or even just doubt) is usually based on a belief that you can trust the evidence to lead you to true conclusions about the world.  Doubt about God stems from observing the lack of positive evidence, and disbelief from observing that the available evidence is incompatible with the God hypothesis.  These methods of justifying belief are exactly antithetical to philosophical skepticism, which holds that no amount of evidence is ever sufficient to justify a belief.  Theists, in fact, often (mis-)apply a skeptical argument when they claim that “You can’t prove a negative result,” not realizing that, if true, this argument merely puts their God on exactly the same footing as being a brain in a vat manipulated by alien scientists in the Alpha Centauri system.

P.P.P.S.  (9/7/2013)  I need to correct my statement that Nozick's concept of "tracking" is just a special case of justification.  (He is at pains to distinguish them on p. 267, by which time I was in a position to realize what he meant.)  Tracking, like truth, is external:  our methods really do track truth.  Justification is internal: we believe our methods track truth, and are therefore reliable or justified.

Saturday, December 5, 2009

Episteme

I have two fundamental epistemological premises: that the evidence of my experience is the best available (really only available) data I have for learning about the world, and that most people who study, think, speak and write about the world are not intentionally lying. These seem to be pragmatically a minimal set. I don’t see how one can practically set forth on the project of learning without them.

Note that the use of the words “most” and “intentionally” in the second premise imply two corollaries: some people are lying, and some people may be unintentionally stating mistruths. (In fact, I might argue that we are all unintentionally stating mistruths to a greater or lesser extent, but that would be more of a theorem than a premise.) Also, saying experience is the “best available” data doesn’t imply that it yields infallible insight.

The two premises do not form a complete (i.e., sufficient) set. All they really say is that I can trust what I experience, and what people tell me about what they experienced (including second or third hand, etc. reports) – but with a grain or two of salt. They don’t say anything about how to come up with that grain of salt, or to know how many grains to apply. They don’t, in other words, tell me how to distinguish the veracity of conclusions I draw from these sources, or how to distinguish between competing theories. They don’t specify any rules of inference, at all.

I’m afraid all I can say about making distinctions is, “It’s ad hoc.” I am no Descartes, to offer a single unified answer to the question of how to distinguish true ideas from false ones. Certainly, I do not believe that because I can hold some idea “clearly and distinctly” that it must be true (although it might suggest truthfulness prima fascie). Instead, it’s more a matter of how well does an idea “fit in” with the other body of ideas I have constructed, over time, from the same evidence. “Consistency”, in a word. But how do I decide if an idea is consistent? Certainly not the idea of the excluded middle. I am quite convinced that it is possible for a thing to be both A and not A. The clearest examples come from human emotions: do I want to spend a month’s vacation in Venice this year, even though the press of work before and after will be terrible, it will cost a lot of money, my Italian is rusty, and I will have to find a house-sitter and/or worry about my pets and everything else in my house? I do, but I don’t. Fuzzy logic may offer better (if inherently less certain) models. But I am convinced that real antinomies can also be supported, as matters of fact (at least as humans perceive fact) in the real world, as well. Or at least, I’m not convinced that they can’t.

Ad hoc. I know it when I see it. Maybe. More or less. (I do, but I don’t.) Kind of like Descartes, perhaps, except I substitute “vague and fuzzy” for “clear and distinct”?

This could be depressing, if, like many philosophers past, I desired the nature of my mind (or soul) to approach some ideal of perfection – to make me like a god. But I don’t believe in gods. Rather than being depressed at failing to approach a fictional divinity, I prefer to celebrate the humanness of it all. Because this messy, ad hoc, but often very effective process of distinction is the stuff of life, after all, and quintessentially human, if only because humans, by and large, do it exceptionally well. Not that we do it infallibly – there are a lot of people in the world who are dead certain of things about which I am certain they are dead wrong. But by and large, in the billions of tiny, every day distinctions and decisions we make over the course of our lives, we do mostly pretty well.

We do this, of course, because we’ve been programmed that way by natural selection. Our brains have evolved to do a job, and they do it rather well (just as flies fly very well, and frogs do an excellent job of catching them). We have certain decision making processes built into our equipment. By studying our thinking in a natural scientific sort of way, it is possible to get clues as to what they are. Philosophers, I think, who have tried to set rules of thought start with some biological rule and then codify it – so clarity and distinctness counts, biologically, as evidence, and so, on some level, does the excluded middle. But we can’t stop there. We move on to fuzzy logic, paradigmatic categories... and who knows how far beyond?

My guess is that, as in most things, the brain works by having a bunch of rules, without any necessary regard as to whether they are consistent in any a priori theoretical sense. Different rules are stimulated by a particular experience, others suppressed, memory of past experience and feedback loops are brought into play, until the system “settles” in some state (“settles” is a relative term for a system that is constantly in motion), and we feel that this “makes sense” or doesn’t. This is what I mean by “consistent” with the rest of my body of knowledge. It is, in fact, the biological basis of, in a sense the definition of, “consistency”. The rules exist because, at some time in the past, they have been found helpful in negotiating the world – they have been empirically proven. They may be “hard coded” rules, proven in the dim historical past of our heritage, but, again like most things in the brain, the “hard coded” rules can be modified, and new rules created, by our individual experience. And such learned rules may be passed on to subsequent generations via the “Lamarckian” evolutionary process represented by our culture and its systems of education.

Thinking in this natural historical way about distinction and rules of inference, etc., may not “prove” validity, in the sense that philosophers have traditionally sought such proofs. But it may give pretty damn’ good evidence of empirical functionality. And, I would argue that this empirical, matter-of-fact kind of “proof” is most suitable to our real-life existence as human beings in a material world, even if it fails for some fictional existence as souls aspiring to a divine one. If philosophy is the pursuit of the “good” and if good must be good for something, then this is the kind of knowledge and truth that is “good for humans”.