Saturday, July 4, 2009

On Truth and Information

In recent years, several philosophers of computing, such as Fred Dretske(1932-) and Luciano Floridi (1964-), have established to a great many people’s satisfaction that for something to be called information, it should allow us to learn something that is true. They argue that false information is not information, just as a false policeman is not a policeman.

In my June 20 contribution to this blog I rather incautiously mentioned the pursuit of the truth about (the laws of) the physical world, and I hinted that I felt this was not the business of science, or research for that matter. Truth is a great concept and a noble ideal, but as I mentioned in the April 18 contribution, the more truthful we make any statement, the less clear it is, and the narrower the scope of its application. In a way, the only absolutely truthful statements are the formal tautologies of pure mathematics, the necessary truths that depend on nothing, and so add nothing to our knowledge. Conversely, any statement that is not necessarily true is merely (by definition) contingently true. It might be true, that is, if (um..) everything were really as it says. There are few philosophers, and even fewer scientists, who feel that this sort of circular discussion is worth while.

And yet, precisely this kind of argument has fascinated people for millennia. Descartes’ necessary truth “cogito, ergo sum” (1641) was the start of his argument to prove the existence of God and the immortality of the soul. A very similar exercise by Bernard Lonergan (1904-1984) achieved a wide currency in 1956. Now the reader should always smell a rat if someone claims to prove a contingent truth from a necessary one. The Australian philosopher David Stove (1927-1994) catalogued a large number of such arguments from Plato to Habermas: explaining that since they want to make everyone accept their opinion, it is a good trick to make it appear merely a logical deduction from a necessary truth. The trick can be made to work, as he explains, with the support of some impressive but contradictory concept, in the same way that division by zero can be used to create a convincing-looking proof. Usually though, such philosophers are vainly trying to use logic to establish some belief which predates their attempt and will outlast their failure.

To return to computing: every piece of information, according to all of us who follow Floridi and Dretske, contains its very own claim of contingent truth. By labelling it as information, we claim that it is not just some sample data: it will allow a suitably placed observer to learn something about the real world (Dretske 1981), at the time the information was constructed. This field of thinking has its own thought-experiments, for example, a bear-track in the woods contains the information that a bear passed that way whether or not anyone ever notices the spoor, and anyone suitably placed to notice it can learn this content.

The raw data from a survey, or a sheaf of newspaper cuttings, may well contain a lot of information that can be drawn to our attention by a suitably placed researcher. Unlike the bear-track in the woods, however, the survey was collected, and the newspaper articles written, by humans who have well-known tendencies to misperception, mistake, misinformation… So while the Internet doubtless contains a lot of useful information, I know it also contains much that is erroneous, ill-informed, and misleading. In research we don’t accept any of it uncritically. We try to stick to good sources of information, we try for honesty in our evidence gathering, and we try to take care in our conclusions, in our mission to increase the stock of knowledge in our academic discipline.