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Sat, 21 Jan 2006

Philosophers. Grrr.

Every morning I wake up to Radio 4. Usually The Today Programme. But a few days ago, I overslept and when I woke up the radio was still on, and had moved on to In Our Time, which had a bunch of philosophers arguing about relativism. One of them made the absurd statement that there is no such thing as absolute truth even in science.

Now, he does have a point, at least to a limited degree. Lots of people who really should know better put too much faith in the scientific method. And I use the word "faith" advisedly! With the physical sciences, you can, in general, really only prove negatives. For example, if someone states that all badgers carry bovine tuberculosis, then he can't actually prove that unless he checks every single badger in the world for bovine TB. Physical scientists will usually accept something like that if experiments consistently produce results in line with the theory for long enough. But really all they're doing is accepting that it is likely to be correct at such-and-such a confidence level. There is in fact no proof whatsoever that all badgers carry bovine TB, and will not be until someone performs that experiment of checking every single badger. The scientific method in this case is merely a tool for getting successively better approximations to the truth, but does not reveal the truth.

There is, however, one class of absolute truth in the physical sciences. That is the negative truth. If instead of suggesting that "all badgers carry bovine TB" we instead posit that "not all badgers carry bovine TB" then that can be proved. All we need to do is check badger after badger after badger until we find one that does not carry the disease. Then we stop, having found the one example of a TB-free badger that is sufficient to prove our theory*. We will only end up doing an exhaustive search of the universe if our theory is wrong.

<light-hearted>In fact, I think there is one absolute positive physical truth. "Something exists in the universe". Even nihilists have to accept that while everything around them might be an illusion, something has to exist that can believe that everything around it is an illusion. Paradoxically, at least the belief that nothing exists has to exist.</lighthearted>

So much for physical science and the scientific method. We have shown that there are at least some absolute truths in physical science. Let us now turn to non-physical science. There is a branch of science which has a whole raft of absolute truths, both positive and negative. I refer, of course, to mathematics. A mathematical proof is far more rigourous than "proof" in the physical sciences**, and is not subject to interpretation or to point-of-view. For example, it has been proven absolutely that the list of prime numbers has no end.

It's fairly obvious that this philosopher was dead wrong in his claim. We have demonstrated the existence of absolute proofs in the sciences right now, never mind what absolute proofs might be found in the future. But I can accept philosophers being wrong. Some of them have to be, given that their field of expertise*** quite happily contains absurd contradictions. What really irritates me, however, is that no-one else, not the other philosophers, not the presenter, thought to correct this obvious error.

* I am ignoring the possibility that the test for bTB might be flawed or statistical in nature. My point is not about badgers but about what sorts of truths can be ascertained absolutely.

** which is itself far more rigourous than "proof" as accepted by courts of law. Courts accept proof "on the balance of probabilities" or "beyond reasonable doubt". Scientists, even those in the physical sciences, like to prove things beyond unreasonable doubt too.

*** this is a variant spelling of bullshit

Posted at 23:13 by David Cantrell