Thursday, December 1, 2011

Meaning and information

I don't remember meeting him, but, when I was a child, we often used to drive past a house belonging to my father's old colleague, 'Sticky' Glew. (My mother had been introduced to him, and had trouble deciding how to address him. She wisely opted for 'Mr Glew'.) It amused my father that his friend had written a dissertation on 'the meaning of meaning'.

"For thousands of years," writes Seth Lloyd (in his book, Programming the universe (Vintage, 2007)), "philosophers have tried to determine what 'meaning' means, with mixed success." (p. 24)

Lloyd's work (in quantum computing and quantum communication systems) is based around the technical concept of information. But strings of bits and so on mean nothing in themselves: they are meaningful only if they can be interpreted. "Meaning is defined only relative to a scheme of interpretation ..." (p. 25)

"Consider the string of bits ... : 1001001 1101110 0100000 1110100 1101000 1100101 0100000 1100010 1100101 1100111 1101001 1101110 1101110 1101001 1101110 1100111. Interpreted as a message encoded in ASCII, this string means 'In the beginning'. But taken on its own, with no specification of how it is to be interpreted, it means nothing other than itself." (p. 25) And, of course, 'In the beginning ...' is interpreted according to the conventions of the English language. As Lloyd points out, natural languages are rich in ambiguity, which is "a key aspect of poetry, fiction, flirting, and plain everyday conversation." (p. 27)

But sometimes, in order to understand basic concepts - like meaning - it is useful to strip away complexities and ambiguities and look at simple models, as Wittgenstein did in his account of language games. Imagine a simple language game in which a builder says "Block" and the assistant hands him a block, or "Slab" and the assistant hands him a slab. The meaning of each expression is to be found in the action the expression provokes.

Lloyd relates Wittgenstein's idea to computers and computing. "The meaning of a computer program written in a particular computer language," he writes, "is to be found in the actions the computer performs as it interprets that program. All the computer is doing is performing sequences of elementary logic operations, such as AND, NOT and COPY ... The computer program unambiguously instructs the computer to perform a particular sequence of those operations. The 'meaning' of a computer program is thus universal, in the sense that two computers following the same set of instructions will perform the same set of information-processing operations and obtain the same result." (p. 26-27)

Meaning, then, is interpreted information. We don't need a theory of meaning such as philosophers have attempted to build. Philosophy (most notably the philosophy of language and metaphysics) has drifted into unproductive areas reminiscent of scholasticism in which intellectual work is done without first ensuring that there is an important intellectual task to address.

Of course, the word 'meaning', like many English words, can be used in different ways, and a careful analysis of the context of use will reveal subtle - and not so subtle - differences. One sense of the word - rather different from most of the others is 'general significance' or 'point' or 'purpose', as in the sentence, 'My life seems to lack meaning.' I have not been talking here of this generalized kind of meaning, but of the ordinary - and primary - uses of the word in relation to information and communication. And, understood as interpreted information, it seems to me a perfectly clear and unmysterious concept. Trying - as some philosophers do - to make a big issue of what they call 'aboutness' or 'intentionality' (which doesn't mean what non-philosophers think it means) constitutes unnecessary mystification.*

The remarkable advances in computing and information and communication technologies during the last 70 years have thrown up many real problems of a fundamental nature, but they require scientific knowledge (not just knowledge of formal logic and philosophy) to address. In particular, the parallels between thermodynamics and information theory are clearly rich in new problems which would benefit from informed reflection. For example, all matter and energy is subject to the laws of thermodynamics, but all matter and energy - everything there is - is also subject to the laws of information. Information theory appears to be a more fundamental and all-encompassing theory than thermodynamics (which can now be seen as just a special case of information theory).

Though I doubt the value of much recent philosophical work in the areas of language and meaning, some very important foundational work has certainly been done by philosophers, philosophically-inclined mathematicians and logicians. The key advances were made during the 19th and early 20th centuries. The work of George Boole, Giuseppe Peano, David Hilbert, Bertrand Russell, A.N. Whitehead and many others provided the conceptual tools which made the development of the electronic computer and sophisticated communication technologies possible. Claude Shannon's development of what he called a 'mathematical theory of communication' and which has come to be known as information theory was based largely on the work of George Boole.

Information has come to be seen as physical - it is no longer seen as abstract, disembodied and unquantifiable. It is always tied to a physical representation: a mark on paper, a charge, a spin, a sequence of bases in DNA. Information processing occurs not just in computers and brains but throughout the physical world.

In 1961 Rolf Landauer came up with a principle with (it is said) startling implications: that one essential information processing operation (erasure) cannot occur without causing heat to dissipate into the environment (thus increasing the entropy of the universe). The processing of information is a thermodynamic process (just as thermodynamic processes are informational) and erasure is an irreversible operation. Negation can be reversed by a second negation. Addition can be reversed by subtraction. But erasure cannot be undone.

I will resist the temptation to discuss the implications of Landauer's principle (which I believe are not good!). I am a layman in these matters, but the role that information processing seems to play in every aspect of nature intrigues me. I am trying at least to understand the fundamental principles, and to relate the sort of thing one learns within the context of philosophical logic - e.g. that there are any number of alternative systems of logic - to the apparently more constrained context of real-world information processing.

* Much philosophical work in recent decades in areas such as ethics, metaphysics, the philosophy of language and even logic has been done by people with a commitment to a religious view of the world (or at least with an anti-physicalist orientation), and has been motivated (I believe) by an attempt to undermine physicalism and to save a space for the spiritual (broadly interpreted). Such a motivation does not invalidate the work, but I personally don't think a convincing case against physicalism has been made.


  1. A great deal of philosophy seems to be stuck on the idea of purpose and existence.
    The age old favourite, prove you exist (based on Descartes' efforts) still troubles some as they strive to prove something on the basis of the approving party's obnoxiousness and facetiousness.
    The exploration of meaning as in the interpretation of what is meant in our communication is valid and useful. Especially in the age of LOLz and increasingly poor grammar habits (I actually had someone criticize my criticism of their post ona chat site because they 'nu wat tey wur sayin adn i had no write to censur tehm'
    If we drift beyond a certain point in our shared rules of meaning and use, we drift beyond a shared language. Even a shared mindset. Like Orwell's Newspeak Dictionary writers said, "a heretical thought -- that is, a thought diverging from the principles of IngSoc -- should be literally unthinkable, at least so far as thought is dependent on words"

  2. Yes, sophont1107, language is at the heart of all things social and reflects levels of social cohesion, values, etc. And there is no guarantee that our languages will continue to work as well as they have. Now English has the added stresses of being a global language as well as - in its various varieties - a first language for many geographically, socially and culturally disparate groups.

    I agree with you that the exploration of meanings through the analysis of what is said and written is a valuable activity but I don't know if it can have a decisive effect or halt the insidious influence of political correctness.

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  4. Mark, physicalists outnumber anti-physicalists by about five to one, in my rough estimate.

    The only well-known anti-physicalists that I can think of are David Chalmers and Richard Swinburne. On the other side we have Dennett, Davidson, Smart, Armstrong, Lewis, Rorty, Searle, Churchland and Churchland, Kim and Fodor.

  5. The more I learn about quantum mechanics, the less I understand it. Fundamentally, for a layman in that area, much of quantum physics has to be taken on authority. Even the authorities themselves do not pretend to understand what is going on (e.g, Feynman). So, when I read recently that the universe itself seems to be made up of information, I had to file it away with all the other challenging concepts from the modern physics lab. Still, if true, would that idea have theological implications?

  6. Alan, I see things rather differently. A few more names ...

    Karl Popper was a Cartesian dualist. Hilary Putnam is a religious Jew, as was Robert Nozick. Peter Geach and Elizabeth Anscombe, Michael Dummett, Alastair MacIntyre, Nicholas Rescher and Charles Taylor are/were all Roman Catholic.

    And Wikipedia calls Rescher one of the first of an increasing number of contemporary exponents of philosophical idealism.

  7. CONSVLTVS, if indeed information is fundamental, this could be seen to have theological implications, I suppose, though both Seth Lloyd and Vlatko Vedral insist that information is physical.

    I see the new approach as potentially giving us a fuller and truer account of reality. The old scientific approaches tended to be tied to an old-fashioned and discredited materialism which left a space which was filled for many by panpsychism or philosophical idealism.

  8. You're right that these people are religious (I didn't know about Nozick). But are they anti-physicalist? Yes, in the cases of Geach and Popper.

    I can't think of anywhere that the others have criticised physicalism. Some are ethicists, not metaphysicians.

    Rescher is a "conceptual idealist", not a metaphysical idealist, I believe.

    You might say that these people ought to be anti-physicalist if they are to be coherently religious. Maybe...

  9. "The meaning of meaning" was a 1923 book title by Ogden and Richards. Maybe that was what Mr Glew was writing about?

    Wikipedia says it has been in print ever since! That's impressive.

  10. If I understand your account of Lloyd's theory of meaning, it amounts to saying that meaning is simply syntax and semantics is not needed. For him (and you?) the idea of "interpreted information" merely means "instructions mechanically followed". There is no semantic interpretation happening. Is this what he is saying?

    It has a few problems!

  11. Alan, I'm saying that people's religious etc. beliefs will inform their approaches to ethics and metaphysics and the philosophies of language, logic and mind. I'm not saying they all explicitly attack physicalism or explicitly defend anti-physicalism. Often the commitments are implicit.

  12. And, Alan, you talk about Lloyd's theory of meaning, but I don't think he has one. I don't think we need one. The best book I ever read on this was Stephen Schiffer's Remnants of meaning which gives up on trying to find a satisfactory theory and settles for a no-theory theory of meaning.

    You're just trying to draw me into that conceptual torture chamber, Searle's Chinese room!

  13. I had a colleague who also favoured a no-theory theory of meaning. It led him to have a no-theory theory of everything. There are no things, he thought. Things are just fictional shadows of fictional meanings.

    There was no room for physicalism in his non-world!