Occam’s shortcomings

In his letter [ FT413:70], John Chordman suggests that we should be suspicious of dyed-inthe-wool sceptics who masquerade as forteans. Sure, but that cuts both ways: also be suspicious of committed believers who masquerade as forteans. He also says that “these individuals are uncomfortable with ambiguity and crave the safe haven of certainty”. Well blow me down and call me an old “sceptical chymist” – I’d always thought that it was the believers who required certainty. As a scientist, I am happy with uncertainty and ambiguity, that’s just the way life is. Because of this, my scepticism varies from subject to subject depending on the level of evidence offered. This means that I find the claims of, say, astrology and graphology risible as so much good evidence exists debunking them. But that doesn’t mean that they aren’t interesting from a more fortean perspective.

Chordman also discusses the sound bite simplicity of the statement “Absence of evidence is not evidence of absence”. Forms of this are used at both ends of the sceptical spectrum. Setting limits on human exposure to various substances often has to be done with poor data – and toxicologists have been known to mutter rather despairingly: “Absence of evidence of effect isn’t the same as evidence of absence of effect”. Ron Gardner

Upton Snodsbury, Worcestershire