Prompted by my discussion of Medawar and recalling that once in the past I called him a gadfly (although obviously I meant it in the good way), Bill Hooker drops another Medawar quotation on me and asks if I'll bite:
If the purpose of scientific methodology is to prescribe or expound a system of enquiry or even a code of practice for scientific behavior, then scientists seem to be able to get on very well without it. Most scientists receive no tuition in scientific method, but those who have been instructed perform no better as scientists than those who have not. Of what other branch of learning can it be said that it gives its proficients no advantage; that it need not be taught or, if taught, need not be learned?
Bill's take is "scientific methodology" here can be read "philosophy of science". So, what do I think?
First off, I'm not entirely sure Medawar was using "scientific methodology" to mean "philosophy of science," so I'll consider the quotation both ways. And of course, I'll have to give some sensible description of what philosophy of science (which is a fairly big and bustling subfield of philosophy these days) might be.
There are lots of things philosophers of science study, but one central set of concerns is what is distinctive about science -- how science differs from other human activities, what grounds its body of knowledge, what features are essential to scientific engagement with phenomena, etc. This means philosophers of science have spent a good bit of time trying to find the line between science and non-science, trying to figure out the logic with which scientific claims are grounded, working to understand the relation between theory and empirical data, and working out the common thread that unites many disparate scientific fields.
If you like, you can think of this set of philosophical projects as trying to give an account of what science is trying to do -- how science attempts to construct a picture of the world that is accountable to the world in a particular way, how that picture of the world develops and changes in response to further empirical information (among other factors), and what kind of explanations can be given for the success of scientific accounts (insofar as they have been successful). Frequently, the philosopher is concerned with "Science" rather than a particular field of science. As well, some philosophers are more concerned with an idealized picture of science as an optimally rational knowledge building activity -- something they will emphasize is quite different from science as actually practiced.*
Practicing scientists pretty much want to know how to attack questions in their particular field of science. If your goal is to understand the digestive system of some exotic bug, you may have no use at all for a subtle account of scientific theory change, let alone for a firm stand on the question of scientific anti-realism. You have much more use for information about how to catch the bug, how to get to its digestive system, what sorts of things you could observe measure or manipulate that could give you useful information about its digestive system, how to collect good data, how to tell when you've collected enough data to draw useful conclusions, appropriate methods for processing the data and drawing conclusions, and so forth.
A philosophy of science course doesn't hand the entomologist any of those practical tools for studying the scientific problems around the bug's digestive system. But philosophy of science is aimed at answering different questions than the working scientist is trying to answer. The goal of philosophy of science is not to answer scientific questions, but to answer questions about science.**
So, if Medawar means to claim that a working scientist doesn't need to have learned philosophy of science in order to get the scientific job done, I think he's right. Neither does a scientist need to have studied Shakespeare or history to be a good scientist -- but these still might be worthwhile endeavors for the scientist as a person. Every now and then it's nice to be able to think about something besides you day job. (Recreational thinking can be fun!)
Now, there are some folks who will argue that studying philosophy of science could be detrimental to the practicing scientist. Reading Kuhn's Structure of Scientific Revolutions with its claim that shifts in scientific paradigm have an inescapable subjective component, or even Popper's view of the scientific method that's meant to get around the problem of induction, might blow the young scientist's mind and convince him that the goal of objective knowledge is unattainable. This would probably undermine his efforts to build objective knowledge in the lab.
My graduate advisor in chemistry had a little story he told that was supposed to illustrate the dangers for scientists of falling in with the philosophers and historians and sociologists of science: A centipede is doing a beautiful and complicated dance. An ant walks up to the centipede and says, "That dance is lovely! How do you coordinate all your feet so perfectly to do it?" The centipede pauses to think about this and eventually replies, "I don't know." Then the centipede watches his feet and tries to do the dance again -- and can't!
The centipede could do the dance without knowing precisely how each foot was supposed to move relative to the others. A scientist can do science while taking the methodology of her field for granted. But having to give a philosophical account of or a justification for that methodology deeper than "this is what we do and it works pretty well for the problems we want to solve" may render that methodology strange looking and hard to keep using.
Then again, I'm told what Einstein did for physics had as much to do with proposing a (philosophical) reorganization of the theoretical territory as it did with new empirical data. So perhaps the odd scientist can put some philosophical training to good scientific use.
Could Medawar have possibly meant, in the passage quoted above, to say that scientists don't need to learn the scientific method? This wouldn't be an outrageous claim if the "scientific method" in questions was an idealized system of steps (like those in the narrow inductivist picture of scientific inquiry Hempel dismisses) that isn't what scientists actually do. There might even be something to the idea that people really learn the kind of scientific that matters by doing science rather than by reading about it or listening to someone lecture on it.
The wee concern I have with this is that, despite the fact that scientists in different fields have expertise with different specific tools and methods, there seems like there should be a common core that unites the patterns of inference they all deploy -- else what would put them all under the umbrella of science? Couldn't that common core be a "scientific methodology" worth learning, if only so the scientist studying bug guts understands how her inquiry is similar to that of other scientists?
Or is Medawar's idea that the needed patterns of inference don't need teaching for some other reason (maybe because they are part of our common sense)?
*For the record, I find science-as-actually-practiced -- in particular scientific fields, rather than generalized as 'Science" -- more philosophically interesting than the idealized stuff. But, as one of my labmates in graduate school used to put it, "One person's 'whoop-de-doo' is another person's life's work."
**Really, to answer philosophical questions about science, since historians and sociologists and anthropologist also try to answer questions about science.