The philosophy of science that began with Sir Francis Bacon's view of the disinterested scientist collecting observations culminated in Karl Popper's view that science proceeds by proving good ideas wrong, to be replaced by better ones. Along the way, it encountered Thomas Kuhn's idea that science proceeds by means of mutually exclusive paradigms.

Scientists are not baconian observers of nature, but all scientists become baconians when describing their observations. Scientists are rigorously, even passionately, honest about reporting scientific results and how they were obtained, in formal publications. Data are the coin of the realm in science, and they are always treated with reverence. Those rare instances in which data are found to have been fabricated or altered are always traumatic.

Science is one of the few areas of human activity that is truly progressive.

Scientists are also not popperian falsifiers of their own theories, but they don't have to be: they don't work in isolation. If a scientist has a rival with another theory for the same phenomena, that rival will be more than happy to perform the popperian duty of attacking the first theory at its weakest point.

Moreover, scientists hold verification to a very high standard. If a theory makes novel predictions, and those predictions are verified by experiments that reveal more interesting phenomena, then the chances that the theory is correct are greatly enhanced. Even if it is not correct, it has been fruitful in the sense that it has led to further discovery.

Science does not, as Kuhn seemed to think, periodically self-destruct and need to start over again. However, it does undergo startling changes of perspective that lead to new and, invariably, better ways of understanding the world. Thus, science is one of the few areas of human activity that is truly progressive. There is no doubt that twentieth-century science is better than nineteenth-century science, and we can be absolutely confident that that of the twenty-first century will be better still — one cannot say the same about many other fields of human endeavour.