P. B. Medawar (1915–1987)

Three short essays on what science is and what it can and can't do, by someone who was not only a very distinguished scientist but also a remarkably talented writer. And probably the sort of book that can be read and appreciated equally by working scientists, philosophers of science, and complete lay-people. Always assuming that they aren't the sort to be easily scared by references that leap back and forth between Coleridge, Shelley, Dr Johnson, seventeenth century playwrights and philosophers, and experimental work in immunology...

"An essay on scians" considers a whole raft of assertions about what science is and how it is perceived, often responding to them in unexpectedly playful ways — for example, he suggests that one of the joys of science is that essentially anyone can do it, and as a career-path it is, like sport in developing countries, a great way for ambitious young people from modest backgrounds to widen their horizons.

"Can scientific discovery be premeditated?" argues against the fashionable idea that scientists should be commissioned by funding bodies to answer specific (useful) questions: he points to numerous examples where someone researching in one field has made a discovery that turns out to be useful in quite a different area (e.g. x-rays). But he doesn't want us to call this "luck" — scientists go into such situations with their eyes open, and have trained themselves to see possible connections and crossovers.

The title-essay "The limits of science"looks into the consequences of the idea that there are certain types of question that are not susceptible to scientific examination — the famous "why are we here?" type of question. Medawar rejects the approach that these should be dismissed as not being valid questions: obviously they are questions some of us have a real need to ask. But he doesn't accept that this means we should put forward myth, metaphysics or religion as a more valid (or even equally valid) way of answering such questions. As long as they do not provide answers that can be empirically tested, he's not buying it. (But he does accept that metaphysics, in particular, can help to suggest ways of approaching difficult questions that scientists can learn from.)

"Limits" also provokes him to ask whether there is a built-in limit to the potential of science to answer questions that are susceptible to scientific investigation, just as there seem to be hard limits to things like population growth or the maximum size of aircraft. Is there ever going to be "too much knowledge" for scientists to keep an overview and do useful research into new things? He doesn't think so. The notion that there was ever a time when "one person could know everything" is silly, people have always specialised and worked in teams, and they continue to do so. Perceptively (given that he was writing in 1984, at the end of a long career), he also points out that computer databases have eliminated the need for an individual researcher to carry any but the most relevant technical knowledge around in their head.

Lovely writing, clear thinking, and only a hundred pages long. What's not to like?… (more)

This collection of eight pieces by Sir Peter Medawar, who shared the Nobel Prize in 1960 for his work in graft rejection leading to advances in the toleration of transplants, is anchored by the last two essays, “Two Conceptions of Science” and “Hypothesis and Imagination.” The point of the title is made in a review of Arthur Koestler’s The Act of Creation, which Medawar finds disappointing because Koestler does not, as we might have expected and hoped, tell us anything from the artist’s viewpoint that shows how scientists go about creative activity. Medawar believes Koestler doesn’t understand how scientists work and that he is not in sympathy with them. Instead, he wants to draw metaphoric parallels among kinds of creative activity and then insist that the purely formal parallels somehow reflect real ones. To Koestler’s complaint that scientists don’t seem to tackle the big, hard questions, Medawar answers that “no scientist is admired for failing” and that if politics is the art of the possible, “research is surely the art of the soluble.”
The pieces here contain a devastating review of Teilhard de Chardin’s The Phenomenon of Man. Medawar bemoans the fact that, since Kant, many have “the mischievous belief” that obscurity means profundity. To the extent that an argument is discernible in de Chardin’s book, Medawar thinks it is fallacious, and blames the author for everywhere using terms that have real and circumscribed denotative meanings and proceeding to treat them as if they were capable of meaning almost anything. Medawar also talks about the work of two nineteenth-century biologists, D’Arcy Thompson and Herbert Spencer, and in another essay speculates that Darwin was not suffering from hypochondria or a “psychogenic” disease as his doctors seem to have believed, but may in fact have contracted Chaga’s disease, caused by Trypanosoma cruzi, a microbe carried by a blood-sucking South-American kissing bug. Medawar also includes his presidential address to the British Association, which gives a retrospective short summary of some of biology’s notable changes in the previous three decades.
His general subject in the book is to explore what scientists are and how they go about their work, and he concentrates on these questions in the last two essays. Science isn’t accumulated fact, as the public generally believes, writes Medawar in “Two Conceptions of Science.” It progresses by subsuming particular facts within general statements, and in that sense it gets simpler rather than more complicated. Moreover, the general notion that scientists are becoming more specialized is not true either: they are more dependent than ever on evidence and discoveries in related fields. One conception of science is that it is an imaginative activity of ideas that needs to be pursued in freedom and the individuals who do it need individual support. Science and poetry are cognate activities in this view. Another conception sees science as a critical and analytic activity with usefulness as its only objective measure. Patrons should support projects rather than people, teams, not individuals. Science and poetry are antithetical in this view. Both conceptions are partly true. Medawar blames John Stuart Mill’s description of “the scientific method” for much confusion about how scientists work. Medawar singles out Karl Popper’s The Logic of Scientific Discovery (1934), as reconciling the two opposed conceptions. He makes too much, I think, of the snobbery of preferring “pure” science versus applied science, insisting that “purity” isn’t a determiner of scientific value; explanatory power, clarifying power, and originality are. Medawar doesn’t think there’s a “scientific mind” or single “scientific method.” Moreover, scientists tell stories they know are not completely true—that is, they try to find a narrative, a theory that will bring things together in explanation. He continues this same discussion in “Hypothesis and Imagination,” reiterating points he made in the previous essay and reducing them to axioms:
“There is no such thing as a Scientific Mind….
There is no such thing as The Scientific Method….
The idea of a naïve or innocent observation is philosophers’ make-believe….
Induction is a myth….
The formulation of a natural law begins as an imaginative exploit and imagination is a faculty essential to the scientist’s task.”
Looking at the history of those who’ve commented on how a scientist works, he notes that eighteenth- and nineteenth-century experimental workers (William Whewell invented the word scientist, along with a great deal more useful terminology: anode and cathode, physicist, eocene, miocene, pliocene, among others) knew that a hypothesis even precedes observation—there is no innocent eye; the mind can’t register the “facts” without a matrix or pattern in which to fit them. The “hypothetico-deductive system” Medawar says is first fully argued in Popper, but it was anticipated by Dugald Stewart and William Whewell in the nineteenth century and even to some extent by John Gregory in the eighteenth. On the matter of induction, Popper is explicit in pointing out that “the only act which the scientist can perform with complete logical certainty” is falsification—disproving his hypothesis. It is in this sense that induction is a myth, since positive results do not “prove” a hypothesis, which still remains tentative. Scientists, says Medawar, have to have the further imagination to see what else would follow from their hypotheses, aside from that which they are trying to explain, and the imagination to devise tests for these other phenomena. Getting at how a scientist actually works is the more difficult since the major product of science, scientific papers, do “not merely conceal but actively misrepresent the reasoning that goes into the work they describe.”… (more)