From “A Cabinet of Philosophical Curiosities”, Roy Sorensen:
When I joined the philosophy department at Washington University in St Louis, I was pleased to see a room with the plaque:
Rudner Memorial Lounge:
In memory of RICHARD RUDNER distinguished philosopher, colleague, and friend.
However, when I asked about Rudner, no one could remember him.In the ‘The Scientist Qua Scientist Makes Value Judgments’ Rudner noted that scientists have acceptance rules: believe the hypothesis if and only if it has a probability above a threshold, say 0.95 or perhaps 0.99. The threshold for belief varies in accordance with how bad an error would be. That is a value judgement.
The stakes are sometimes of existential proportion. When developing nuclear energy, some physicists worried that there was a slight chance of a runaway chain reaction. Each split atom splits a neighbour atom until no atoms remain to be split. The physicists calculated that the scenario had a probability of less than four in a billion. They felt that was low enough to dismiss the possibility. Maybe they were right. But that is a value judgement.
How probable must Rudner’s thesis be for scientists to accept it? Well, how bad would it be to be mistaken about whether value judgements are a core responsibility of scientists? Or to forget Richard Rudner and his thesis?
Séamus Sweeney 