But Bayes’ theorem isn’t just an equation for the way humans already make decisions. It’s much more important than that. To quote Sharon Bertsch McGrayne, author of The Theory That Would Not Die: ‘Bayes runs counter to the deeply held conviction that modern science requires objectivity and precision.’31 By providing a mechanism to measure your belief in something, Bayes allows you to draw sensible conclusions from sketchy observations, from messy, incomplete and approximate data – even from ignorance.
