Philosophers of Science have long puzzled over what they call “the” demarcation problem, of how to distinguish science from pseudoscience. In the early 20th Century the Logical Positivists proposed the verification principle, that a statement was meaningful and scientific only if it could be empirically verified. Karl Popper then proposed a similar idea, that a scientific idea is one that can be falsified.
There is a lot of truth in both proposals, but neither can be interpreted too narrowly. The problem is that no statement can be verified or falsified in isolation. Science constructs whole webs of ideas, and it is the whole construct that is then compared to empirical data, to be adjusted and improved as necessary. Further, a statement such as Newton’s law of gravity can never be verified in the general sense, all we can say is that it worked well enough — as part of the wider web of ideas — in the particular instance we tested. Nor is it straightforward to falsify such a law. If our overall model is inconsistent with an observation then we could indeed alter one of the laws; but we might also overcome the inconsistency by altering some other part of the overall model; or we might doubt the reliability of the observations. Continue reading