April’s letter of the month, to Theodore Ziolkowski in May 1983, sees Lewis apparently comparing philosophy unfavourably with science. His starting point is an article in the Syracuse Scholar, ‘Pseudoscience’, by C.L. Hardin. (You can read the article here: http://surface.syr.edu/cgi/viewcontent.cgi?article=1108&context=suscholar) The article is, as Lewis says, inconclusive, but the basic gist of it is roughly this: there is no ‘rock-ribbed’ criterion of demarcation between science and pseudo-science. Nonetheless, ‘at least 95 percent of what one would be intuitively inclined to view as pseudoscience is intellectual garbage and identifiable as such. These are not hard cases; they can be dismissed by good sense and careful detective work’ (p.9). On the other hand, he guesses that in 5-10% of the ‘fringe literature’, ‘one encounters ‘a small number of anomalous phenomena and unusual suggestions for explaining them which seem to merit further investigation’.

Lewis offers the conclusion that, while it’s risky to ignore unorthodox science — some of it, after all, may be true — the expected payoff for searching for the diamond ring in amongst all the garbage isn’t high enough to make it worthwhile to hunt for it. And this brings him to the unfavourable comparison of philosophy with science: we’re always ready to listen to someone with a radical new position, with the result that we tend not to give anything a ‘very thorough examination’.

Was he being serious? I suspect he was. After all, Lewis himself wasn’t prone to taking up other people’s offers to ‘revolutionize philosophy’. He was no follower of fashion (though of course he was a trend-setter), sticking pretty steadfastly to his own philosophical agenda throughout his career. (© Estate of David K. Lewis.)