Progress and non-progress
Let us take as our starting-point one fact on which most people would agree—that, at least according to some definitions of the word, there has been spectacular progress in some areas over the last four hundred years. These areas include physics, chemistry, mathematics, medicine, electrical engineering, astronomy, and space travel.
On the other hand, there are other areas where the achievement of knowledge has been much slower. There would probably be less agreement on the list, but perhaps it would include psychology, sociology, politics, management, law, philosophy, and theology. At least some people would take the view that, far from there being a steady, even if slower, progress in these areas, the movement is more like a following of one fashion after another.
Possible reasons for the difference
You may say that the first group is easier than the second. Or you may say that there is less argument as to what would constitute progress. Or you may say that the first group consists of areas that are scientific, while the other is an area where scientific methods are less applicable—or not applicable at all.
Let us start with the last suggestion. I want to argue that we suffer from the manner in which the proper territory of science is usually defined.
The narrow definition of science
Methodology and subject-matter
People tend to confuse the methodology of science with its subject-matter.
Scientists generally succeed professionally by being expert in a specific subject-matter, and it is a striking fact that even the most successful and famous scientists often seem to have only the haziest idea about the philosophy of scientific method. They can make errors in their attempts to explain scientific method to the general public, and when they stray outside their own specific areas of subject-matter.
That science has its limits
So it is easy to see how it has come about that what has been so spectacularly successful is seen as the area of a particular kind of knowledge about a restricted range of things. It is not seen as the area where a particular attitude and methodology are adopted. Science has come to be seen as having its own limited territory—outside which it is not competent to go, and outside which it would be undesirable to let it go.
However, if we look instead at the methodology which has been so successful, the question becomes one of whether there are different kinds of knowledge, each of which has to be discovered by a different method—or whether there is just one effective way to achieve knowledge, which can be just as successful wherever it is allowed to be used.