Showing posts with label epistemology. Show all posts
Showing posts with label epistemology. Show all posts

Sunday, November 22, 2009

Induction



Will the Sun Rise Tomorrow?

How do we know that the sun will rise tomorrow?

Bertrand Russell, in Chapter VI of his 1912 book The Problems of Philosophy, asks this question of us, as a way of introducing what philosophy has called “the problem of induction”.

No one has yet seen the sun rise tomorrow. However, we suppose that it will, based on what we have always seen in the past. Predicting what will happen with things we haven’t witnessed on the basis of things we have is called “induction”.

As likely as it seems that the sun will rise in the morning, what we know of astrophysics tells us that a comet may hit the earth tonight and knock it off its orbit before our first cup of coffee on the morrow. We cannot know the future as concerns the sun, nor indeed can we conclusively know anything about anything else for which we have no already existing empirical evidence.

It is extremely valuable to always be aware of this unfortunate reality, for it reminds us that even the most rigorous science is fallible. In effect, induction is a kind of informed guesswork, and we are wise to approach all claims based on induction with a measure of skepticism.

Is guesswork a sufficient proof of anything? Can we use it as a guide to our actions in the future? This is the problem of induction.

Saying that we can never be absolutely certain is a useful observation; to say that we can never be reasonably sure is not.

Russell does not explicitly state that one can never use past experience as a guide to future experience; only that to do so one must use what Russell calls, rather grandly, the “principle of induction” This principle is best summarized by Russell himself. We cannot expect certainty about that which we have not yet directly observed; therefore “…probability is all we ought to seek.” (Russell, p. 66)

Human beings are active, agentic creatures, pushed and pulled about by all manner of internal and external motivations, who seek knowledge not for its own sake, but because knowledge serves as a guide to action. Knowledge is a tool a person uses to accomplish a task. Knowledge must be useful and usable to qualify as knowledge. Knowledge which has no use is, by definition, useless; we often describe it as “useless information”.

This formulation can help us distinguish between knowledge and information. Knowledge has an immediately discernable use-value. Information that has no recognizable use-value is not regarded as genuine knowledge, and our brains don’t for the most part retain such information.

Human knowledge therefore relies on induction, for if knowledge is something to be used, it must be reasoned through induction that it can be used in some unknown and unreliable future. When we walk from point A to point B by putting one foot in front of the other, we induce that since our last step found solid ground, so our next step will fall on solid ground. Of course in our millions of steps there come times when this innate knowledge proves fallible.

In order to determine the usefulness of anything, we must use our powers of induction. We have had experience of this cause and that effect; we predict that a similar cause in similar circumstances will produce a similar effect.

Thus the concepts of inference, prediction, and induction inhere in the concept of knowledge. Knowledge is a hypothesis about the unexamined on the basis of the examined. The previously examined is no more than information, unless one can use it to predict the future. The sun rose yesterday. So what? A conclusion from induction – say, that the sun will also rise tomorrow – is a hypothesis on which one can base useful action, however certain we are that such knowledge will ultimately prove unreliable. Anyone who claimed to know no more about the sun than that it rose yesterday cannot claim to truly have knowledge of the sun.

This important point needs to be restated. Knowledge is inseparable from the intention of the knower. Knowledge is not a dry thing that lives on a shelf in a library. Knowledge is inseparable from the act.

Induction differs from deduction simply in that the conclusions of an inductive argument are never certain. At best, induction can point to a reasonable probability, such the probability that the sun will rise in the morning. Deduction can point to certainty, but only through a sort of sleight of hand.

Here is an example of a deductive argument:

1. All mammals suckle their young.

2. Foxes are mammals

3. Therefore, foxes suckle their young.

On the face of it, this seems a bulletproof argument, until we remember that the whole thing hinges on our definition of “mammal”. Part of what defines an animal as a mammal is that it suckles its young. Thus a deductive argument brings nothing new to the table – it merely allows us to make something more obvious.

It is only induction that allows us to make the great leaps in knowledge of which humanity is so rightly proud. Our intelligence as a species is really our powers of induction. Intelligence can be regarded as the ability to predict the future from the past – and Jeff Hawkins does so in his book, On Intelligence.

Knowledge is a guide to action based on probability. All projections for the future are of course based on an analysis of the past. All knowledge is therefore empirical. Probability is in fact an empirical principle. It has been repeatedly proven on the basis of empirical evidence that given a sufficient sampling it is possible to predict, with a reasonable degree of certainty, that the future will resemble the past. Of course, one needs a large enough sampling, and one needs to allow for a greater or lesser margin of error. Saying that probability theory is based on empirical research does not mean its predictions are deductively conclusive or constitute certain proof.

The best probability theory can offer is a prediction that given certain circumstances a given course of events will occur within a range of frequency – most of the time. And in this topsy-turvy world, perhaps, in the words of Russell, “…probability is all we ought to seek.”












Wednesday, June 24, 2009

Is belief in the external world a hypothesis?



In the first three chapters of his book, The Problems of Philosophy, Bertrand Russell makes the case that we cannot know for certain whether there is actually a real world outside of and independent of our perception of it. Is belief in the external world a hypothesis?

Understand first that a hypothesis is a sort of educated guess. It is a conjecture, an idea, a reasonable suspicion, to be proven valid only by experience, and by experiment, experience’s substitute teacher. Yet even a valid hypothesis is not a certainty.

That a real world exists is a sound hypothesis, with much evidence to hand in support – but it remains a hypothesis. Russell argues that we cannot ever know or prove the independent existence of reality to a level of absolute certainty. I think he’s right, and I’ll go one better by saying that while we can know things well enough to suit our purposes, I don’t think we can ever know anything for certain.

Russell argues, for instance, that we can only know our own sense-data for certain. However, the existence of such phenomenon as “phantom limb syndrome”, wherein amputees feel distinct sensations from missing limbs, proves that even our own sense-data are suspect. I find Russell’s arguments shaky throughout, but due to constraints of time and space, I will try to address only a few select issues in this post.

Russell spends time discussing tables and the properties thereof, using them as an example of something real and commonplace that we take for granted. He argues that:

1. Our understanding of such a thing as a table comes not directly, but through sense data.
2. Sense data are not identical to the table itself.
3. What we know is therefore not the table in and of itself, but sense data
4. Sense data are unreliable and superficial representations of physical objects
5. Therefore the real table, and by extension, the real world is not truly known to us.

Although I agree that the existence of the external world is a hypothesis, Russell’s argument for this conclusion hinges on a common but fallacious assumption about knowledge, namely that knowledge is data. That the data we do have about a physical object may be incomplete or inaccurate does not negate our knowledge of that object.

The assumption that data is knowledge can be easily refuted, as anyone who has worked in the world of computers can attest. Computers can amass vast quantities of data and store it in databases. Is this knowledge? If it were, we would not have a separate word, “data”. But data is not completely separate from knowledge – it has the potential to inform knowledge.

The telephone company records every second that every cellphone customer spends connected to their network, and stores that carefully in company databases. Look at this data closely and you will discover that it’s a jumble of ones and zeros. Look at sense data closely – and science has – and you will discover it’s a jumble of bio-chemical and electro-chemical reactions. Is this knowledge?

Not yet – it has a long way still to go. First this data has to be organized into meaningful elements and components. It has to be put into a formation that is intelligible to the human mind. It is the job of the modern Information Technology (IT) department, and the computer programs they develop, to turn data into information – to put data “in formation” – so that it can be interpreted by a human being. Out of a mountain of data comes a series of reports, prepared by computer programs. Now the data has been turned into information. But is it knowledge yet? If mere data does not constitute knowledge on its own, does information?

Not yet – it still has a way to go. When I connect to the Internet, I can connect to billions of pages of information. The Internet is a galaxy of information, and I have access to all of it. But does having all the world’s information at my disposal, however well organized and well “in-formed” it is, mean I have all the world’s knowledge?

Of course not. Knowledge is more than data and more than information. If it were not, we would not have a separate word for it. But what is that secret sauce that turns a sandwich into a banquet?

When management at the phone company reviews the dozens of reports produced by the IT department, they don’t do so to admire the quality of the paper or the readability of the typeface or the logic of the categorization of the information. They review those reports in search of something actionable. They ignore information that can’t be used, however well “in-formed” it is, because information that can’t be used is by definition useless. And can we describe useless information as genuine knowledge? Of course not. For information to be regarded as knowledge, it must be useful for something; it must have a use-value. What good is information if you don’t know what to do with it? Knowledge is information that is usable. Knowledge is information with a use-value.

And here we can return to Russell’s arguments about sense data. Science has shown that our senses receive signals from the environment, some of which may indicate the presence of a physical object such as a table. Of course, our experience of the table is not immediate, but is mediated, meaning it comes to us through various media, among them light waves and sound waves, which tell us of the existence of the table.

Russell and many of his critics seem to agree that if our perception of the table is not immediate, it is invalid. Why this should be so is quite unclear, for surely we can perceive the table through various media, and can do so reasonably reliably.

This data is received by our sensory organs as a blooming, buzzing confusion. Our minds seek to arrange or formulate this data into some sort of meaningful, recognizable pattern. (This is why we sometimes see castles in passing clouds or a face on the moon.) This activity is analogous to the activities of the IT department at the phone company, when it turns mountains of data about cellphone use into meaningful information.

As Jeff Hawkins points out in his recent book, On Intelligence, our minds then engage in an extremely rapid process of comparing this sense-data to previously learned patterns, looking for something relevant. Our minds may be able to match patterns of incoming sense-data to previous experience, and if they do, the sense-data is translated into meaningful information.

This is a table, on the table is a cup and a pen and paper. There are two chairs, the floor is hard, and there’s a scent of flowers in the air, and the temperature is slightly cool. All this information is assembled from sense-data, given formation through pattern-matching and language, and then ever so briefly reviewed by the mind to determine how useful it is.

If on entering the room a colleague throws you a tennis ball, everything you have perceived, consciously or unconsciously, falls away, discarded by your brain as just so much useless information. Your brain focuses on the task at hand, catching or avoiding the throw. The sense-data that your mind translated into information about the ball has now become useful knowledge. Thus intelligence moves from data to information to knowledge.

No analogy is perfect and the analogy between our minds and computer and information processing technology is full of holes. But the parallels are sufficient to suggest that we may have created electronic information processing on the model of our own mental processing.

So what was missing in Russell’s account of the table? The use-value! How can we claim to any knowledge of such a thing as a table without understanding its use, its purpose, its telos? The moment we introduce the property of usefulness and purpose to a physical object, we possess the key to knowledge of it, because the concept of utility itself includes the concept of the relation of the physical object to humanity.

The very word “table” is a human construct, a symbol intended to convey the use of a physical object to other human beings. Its use as a word contains the implication that humanity has a relationship not only to tables, but to the physical world. This object before us is something that is reasonably flat and stable, so one can put a cup or dish on it without spilling, write a legible note on its surface, etc. It can have four legs, three legs, no legs, or it can be a stump or a flat rock. If we focus on data about the table – its color, how many legs it has, the material of which it is constructed, how its surface looks under a microscope, etc. – and ignore its use, as Russell and other writers appear to do, we will never really know or understand the table or the qualities of tableness.

There are numerous attributes of any particular table that are more or less irrelevant to its use-value as a table, and indeed to its status as a representative of the class of tables. These qualities fall mainly under the heading of “Useless Information”, and should therefore not be the yardstick by which we measure our knowledge of such a thing as a table. To do so, as it seems Russell and his critics have done, is to miss the point.

We don’t have all the data about a table or any other physical object, and indeed can never have it. Furthermore, because our perception of the table is not immediate, it is subject to any number of distortions internal and external to the perceiver. For these reasons and others, the existence of the external world remains a hypothesis. It is nevertheless a fairly sound hypothesis and a reliable guide to action – and that’s good enough.

One can only know the physical world insofar as one knows the use to which one seeks to put it. Our understanding of physical objects is inextricably linked to our intentions towards them, and the failure to recognize this can only result in the sorts of philosophical absurdities Russell warns us never to be frightened of…

References

Russell, Bertrand (1997). The Problems of Philosophy. New York, Oxford University Press.
Hawkins, Jeff (2004). On Intelligence. New York, Henry Holt and Company.

Sunday, February 03, 2008

Knowledge and Experience


I’ve argued in an earlier post that knowledge is information that has a use-value. The importance of truth to knowledge is whether that knowledge is reasonably reliable – in which case it can be described as true.

What is the source of knowledge?

Traditionally, there are several sources:

• Authority
• Revelation
• Intuition
• Personal experience
• Inductive reasoning
• Deductive reasoning
• Instinct
• Science

Knowledge by Authority

Authority is knowledge passed down from an individual or institution. This sort of knowledge is best used as a sort of rule of thumb for decision-making in areas in which the decision-maker has no direct experience or other heuristics to draw upon.

The problem with authority as a source of knowledge is that it may be unreliable. Authorities have their own agendas to promote, and may not always have based their own authority upon solid ground.

The most reliable authorities have based their knowledge on their own experience or the experience of the institutions they represent. There is nothing wrong with respecting authority if that authority is deserved, especially if that authority has provided valuable and reliable knowledge in the past.

We could not possibly be expected to know the law, medicine, physics, plumbing, or any other area of expertise without extensive training and personal experience. Therefore it is reasonable to respect an opinion in these areas from an accredited practitioner as a guide to correct action.

It goes without saying, however, that some forms of authority cloak vested interests, and may therefore be valid only insofar as they support those interests. Religious authority, corporate authority, or political authority are especially suspect, since they may offer only partial truths while ignoring most of what might undermine their agenda.

My point here is only that knowledge by authority is based on experience – not personal experience, but the experience of the authority themselves.

Knowledge by Revelation

One common meaning of revelation is truth “revealed” by the divine. Typically this truth is revealed to an individual.

There is no doubt that an individual can achieve a truth through a sudden epiphany or blinding insight. Whether this insight is valid remains to be proven in practice, and whether or not it is of divine origin may never be provable.

Revelation is an intensely subjective experience and almost by definition is neither repeatable nor verifiable. This makes it a rather unreliable guide to action and a weak base of knowledge.

Knowledge by Intuition

Intuition is often regarded as “gut sense”, an insight gained on a non-intellectual level for which there appears to be no rational justification. But as Malcolm Gladwell’s book Blink made clear, intuition is in fact a very rapid calculation made on an unconscious level, but based on genuine observation and often very sound mental and emotional reasoning.

One may feel as if one knows something by intuition alone, based on nothing more than a vague “feeling”, but dig a little deeper and intuition proves itself to be a device for rapid pattern recognition at a pace faster than can the mind can follow.

All pattern recognition is based on past experience of that pattern. If we take Jeff Hawkins’ work On Intelligence, all intelligence is not more than the ability to predict based on pattern recognition. In other words, all intelligence is based on experience.

Knowledge by Personal Experience

Knowledge by personal experience is obviously valid if it works for you. But it goes without saying that just because something works for you doesn’t mean it will work for others, and just because it works for you doesn’t mean that it is the best way to do things. Knowledge by personal experience is most valuable if confirmed by the experience of others.

Knowledge by Inductive or Deductive Reasoning

Inductive reasoning is the process of generalizing based on specifics. For example, every duck I have ever seen can swim; I can therefore induce that all ducks can swim. Deductive reasoning moves from the general to the specific. For example, I know that all beetles are insects and therefore by definition they have six legs. Therefore I can assume that all beetles in Uruguay have six legs, even though I have never been to Uruguay.

Both types of knowledge are obviously based on experience.

Knowledge by Instinct

Instinct is not typically seen as a form of knowledge, but as I have argued in an earlier post, what we call instinct is the summary of the experience of the previous generations of our species, as recorded in our genetic materials.

Knowledge by Science

Science is knowledge obtained through the scientific method. The scientific method is nothing more than the systematic and thorough testing of a hypothesis through experience.

The word “experiment” shares the same root as the word “experience” – the Latin “ex”, meaning “out of”, and “peritus”, meaning “testing”. Experience is knowledge gained through repeated trial.

An experiment is an attempt to create or recreate a certain type of experience through systematic observation and analysis. The purpose of the scientific method is to discover or confirm a repeatable and verifiable outcome of a set of identifiable conditions.

The scientific method, therefore can be regarded as nothing more than the systematic confirmation of experience.

Saturday, June 09, 2007

Science



I listened to a podcast lecture yesterday by Harvard history of science professor Steven Shapin. Shapin argues that science is becoming so loose a term used by so many – think creation science, scientology, etc. – and so few people live by science, that perhaps the term has lost all meaning, and certainly that the modern consciousness is not scientific.

He cites a number of sad statistics about Americans – that more than 90% believe in God, 82% believe in a physical Heaven, 84% believe in the survival of the soul after death, more than 50% reject evolution, that more than 25% believe the sun revolves around the Earth, and so on – as evidence that while people talk as if they respect science, they don’t actually know what it is.

Furthermore he states he has never heard a convincing definition of the scientific method. Which prompts this entry.

Let me start with an interesting point Shapin makes. He points out that at some point in our culture, scientists conceded some important ground to religion. They began to argue that science had nothing to say about morality, in fact that science and morality were mutually exclusive. Science was not about morality, and morality was not about science. They were all too willing to surrender the hard questions to the mystics and the divines, the priests and the pastors, because they had no scientific answers to offer.

One of my goals for this blog is to find a way to bridge science and morality, to show that morality can be explained through a range of scientific discoveries, not least of which was the work of Darwin and his intellectual descendents.

In part this is an epistemological question. Scientists, if they were worth their salt, learned early in their careers that absolute certainty had no place in science. Science is not the search for absolute truths – in fact physics has proven that all is in a state of flux and impermanence, and there are no absolutes.

Aware of this, and no doubt influenced by the religious cultures in which they were born and bred, scientists in the Enlightenment began to argue that their endeavors were much humbler and more practical than those of the spiritual leaders. They operated on a different plane.

Today in America one frequently comes across a curious belief that religious convictions are sacrosanct, above question, and that anyone has the perfect right to believe any sort of nonsense if it seems to have a “spiritual” basis. The rules don’t apply. It’s the split between faith and reason.

This split often shows up in the individual themselves. Something over 50% of American scientists, people who make their daily living from rationality, believe in a God, and seem quite comfortable with this split brain. Orwell called it double-think – the ability to firmly believe in two contradictory ideas at the same time.

Prof. James T. Hall cites a lecture he attended given by an evangelical. The speaker distinctly contradicted himself in his talk. When Prof. Hall questioned him on this, his reply was too the effect that, yes it was true that he had contradicted himself, but that didn’t matter, because “this is not science, this is religion.” Oh. OK then.