In 1970, I had the chance to attend a lecture by Stephen Spender. He described in some detail the stages through which he would pass in crafting a poem. He jotted on a blackboard some lines of verse from successive drafts of one of his poems, asking whether these lines (a) expressed what he wanted to express and (b) did so in the desired form. He then amended the lines to bring them closer either to the meaning he wanted to communicate or to the poetic form of that communication.
I was immediately struck by the similarities between his editing process and those associated with scientific investigation and began to wonder whether there was such a thing as a scientific method. Maybe the method on which science relies exists wherever we find systematic investigation. In saying there is no scientific method, what I mean, more precisely, is that there is no distinctly scientific method.
There is meaning, which we can grasp and anchor in a short phrase, and then there is the expression of that meaning that accounts for it, whether in a literal explanation or in poetry or in some other way. Our knowledge separates into layers: Experience provides a base for a higher layer of more conceptual understanding. This is as true for poetry as for science.
Let’s look at an example that is a little less complex than poetry. Consider how Socrates guided his students to a definition – of justice or knowledge or courage.
When Socrates asked “What is justice?” there was never any doubt that his listeners knew what the word “justice” meant. This is confirmed by the fact that Socrates and his listeners could agree on examples of justice. Defining justice, on the other hand — that is, being able to explain what it was conceptually that all these examples had in common — was something else altogether.
Suppose you and I try to define courage. We would begin with the meaning that is familiar to both of us. This shared meaning will be used to check proposed definitions and provide typical examples of it. Commonly, we may not be able to explain what something is, but we know it when we see it.
So what do we mean by courage? Let’s try, “Courage is the ability to act in the face of great fear.” This is an attempt to articulate (define) what we mean by courage. What we do next is to compare the actual meaning of courage we both possess with the literal meaning of the expression “the ability to act in the face of great fear.”
In comparing this literal meaning with the actual meaning of courage in our minds, we come to realize that the literal meaning of our working definition won’t work because, for example, “to act in the face of great fear” could include tying one’s shoelace, yelling profanities, even running away.
So we must alter our definition to exclude these typically non-courageous actions. One way of doing this is to produce a definition such as, “Courage is the ability to act in the face of great fear, except for tying one’s shoelace, yelling profanities and running away.” This does produce a literal meaning closer to the actual meaning we want to express or define.
Yet we wouldn’t accept such a definition even if it itemized every possible exception. Why? Because, from a different point of view, this definition is inadequate: not because it fails to bring the meaning of the definition closer to the actual meaning of courage, but because all it does is try to save the original definition by tacking on ad hoc exceptions. That is, we reject it because it fails to be a good, well-formed definition. A good definition is simple and provides a principle that would exclude all possible exceptions without having to enumerate them one by one.
What do we do? We come up with a new definition that once again is simple (without adding exceptions). We could try, “Courage is the ability to act while confronting a great fear.” Adding “confronting” would seem to disqualify tying one’s shoelaces and even shouting profanities since one could shout profanities while running away.
Yet adding an ad hoc exception may sometimes be just what is called for. Suppose I define courage as “the ability to act while confronting a danger to oneself.” “Confronting” is retained, so this would (normally) exclude running away. Yet one could also act out of anger, so that courage may not be the principal trait exhibited. We could add the ad hoc hypothesis “except when motivated principally by anger.” This would be desirable in this case, for the phenomenon turned out to be composite — actions that may arise from separate causes (courage and anger).
It’s important to see that this process — like that whereby a poem is written — rests on two requirements that have to be met. A good definition or poem must be one (a) whose expressed meaning matches the actual meaning that was grasped in a pre-articulated way and (b) which satisfies some criterion of form (embodies an explanatory principle or satisfies poetic form).
Now compare this with a scientific example: Johannes Kepler’s discovery that the orbit of Mars is an ellipse.
In this case, the actual meaning of courage (what a definition is designed to define) corresponds with the actual observations that Kepler sought to explain — that is, the data regarding the orbit of Mars. In the case of definition, we compare the literal meaning of a proposed definition with the actual meaning we want to define. In Kepler’s case, he needed to compare the predicted observations from a proposed explanatory hypothesis with the actual observations he wanted to explain.
Early on, Kepler determined that the orbit of Mars was not a circle (the default perfect shape of the planetary spheres, an idea inherited from the Greeks). There is a very simple equation for a circle, but the first noncircular shape Kepler entertained as a replacement was an oval. Despite our use of the word “oval” as sometimes synonymous with ellipse, Kepler understood it as egg-shaped (in the asymmetrical chicken-egg way). Maybe he thought the orbit had to be lopsided (rather than symmetrical) because he knew the Sun was not at the center of the oval. Unfortunately, there is no simple equation for such an oval (although there is one for an ellipse).
When a scientist tests a hypothesis and finds that its predictions do not quite match available observations, there is always the option of forcing the hypothesis to fit the data. One can resort to curve-fitting, in which a hypothesis is patched together from different independent pieces, each piece more or less fitting a different part of the data. A tailor for whom fit is everything and style is nothing can make me a suit that will fit like a glove — but as a patchwork with odd random seams everywhere, it will also not look very much like a suit.
The lesson is that it is not just the observed facts that drive a scientist’s theorizing. A scientist would, presumably, no more be caught in a patchwork hypothesis than in a patchwork suit. Science education, however, has persistently relied more on empirical fit as its trump card, perhaps partly to separate science from those dangerous seat-of-the-pants theorizings (including philosophy) that pretend to find their way apart from such evidence.
Kepler could have hammered out a patchwork equation that would have represented the oval orbit of Mars. It would have fit the facts better than the earlier circle hypothesis. But it would have failed to meet the second criterion that all such explanation requires: that it be simple, with a single explanatory principle devoid of tacked-on ad hoc exceptions, analogous to the case of courage as acting in the face of great fear, except for running away, tying one’s shoelace and yelling profanities.
Yet in science, just as in defining a concept like courage, ad hoc exceptions are sometimes exactly what are needed. While Galileo’s law prescribes that the trajectory of a projectile like a cannonball follows a parabolic path, the true path deviates from a parabola, mostly because of air resistance. That is, a second, separate causal element must be accounted for. And so we add the ad hoc exception “except when resisted by air.”
This is enough. There is much more to a theory of inquiry, of course, that could cover forms as disparate as poetry and science.
An obvious question at this point is this:
If scientific method is only one form of a general method employed in all human inquiry, how is it that the results of science are more reliable than what is provided by these other forms? I think the answer is that science deals with highly quantified variables and that it is the precision of its results that supplies this reliability. But make no mistake: Quantified precision is not to be confused with a superior method of thinking.
I am not a practicing scientist. So who am I to criticize scientists’ understanding of their method?
I would turn this question around. Scientific method is not itself an object of study for scientists, but it is an object of study for philosophers of science. It is not scientists who are trained specifically to provide analyses of scientific method.
A Response from the Author
Thank you to those who took the time to respond to my essay on scientific method. I’d like to offer the following response to address certain issues and arguments that arose in the comment section.
Some readers claimed that I was denying the existence of a method that science employs. I was not. I was arguing against the claim that only science employs it.
The importance and effectiveness of scientific inquiry is not in question here. Philosophers of science have spent centuries trying to better understand it. I have done so by studying both science and philosophy throughout my career, starting with a degree in physics. I should probably add that I strongly oppose creationist and other ideological bents that just don’t want certain scientific findings to be true (e.g., global warming).
Suggesting that the method science uses is its exclusive property is an inflationary claim that doesn’t serve science well. Science is a form of human knowledge. But there’s more to knowledge than science. The differences, of course, have to be preserved, but we won’t know what the defining differences are until we identify what it is that scientific and nonscientific inquiry have in common. This short article was a modest attempt to explore that question.
The point of comparing science to poetry was to focus on what is common to any systematic attempt to move from an experiential level of knowledge to a more conceptual level. We do this in the scientific explanation of observed phenomena, but we also find it in the poetic (or artistic) expression of experience, in articulating a principle of law that is initially only intuited, in devising social, political and philosophical theories, and in such seemingly simple acts as saying what we mean, which may well be quite challenging in itself.
Each of these diverse efforts at articulation also involves testing proposed articulations against the experience that we seek to articulate, and an intelligent correction process in response to error. This is quite complex — something I was not able to elaborate on in the article. (My book “Of Two Minds: The Nature of Inquiry” gives the matter a more complete treatment.) I may devise a theory of scientific advancement, for example, on the basis of my knowledge of developments in physics. The data that I seek to explain are in fact the practices of scientists in their respective areas. If I then test this theory and find that advances in biology follow the same pattern, I have a least partly confirmed my theory.
Other philosophers or historians could then reproduce such a test by using yet other historical developments in biology — or the same developments recorded by other observers. If new data on the historical development of science resist explanation by this theory — and are thereby at least tentatively falsified — philosophers and historians, like scientists, will have to go back to the drawing board.
It is absolutely true that the results of careful scientific investigation are more trustworthy than results in nonscientific areas of inquiry. Nothing in my essay suggested otherwise. Some individuals who commented on this essay acknowledged this feature of scientific investigation by noting that other areas of inquiry have many more variables to contend with; that these variables are often difficult to quantify; and, of course, that human subjective experience may be involved in the phenomena that we seek to understand. These are all important differences.
My essay’s point, however, was to encourage us to think of good investigative thinking and problem solving as spread through all of the disciplines that comprise human knowledge. I realize that people who exclude, for example, poetry and philosophy from our collective human knowledge of nature and of ourselves, may be hard to convince.
The fact that scientists skillfully practice a “method” doesn’t mean that they can articulate what that method is. The fact that I can skillfully speak English doesn’t mean I know its grammar. Artists do what they do. Art critics and theorists, who may themselves have little talent for art, may nevertheless have talent for understanding what artists do. Scientists investigate natural phenomena like galaxy formation and immune system dysfunction: but, in most cases, they do not investigate the logical method they employ in that investigation. Philosophers of science are among those who do.
When scientists do attempt such an account of their method, as is often offered in the introduction to science textbooks, it’s clear to me they are in need of some assistance from philosophers of science. I have written about this in a paper, “How Science Textbooks Treat Scientific Method: A Philosopher’s Perspective,” an empirical analysis of what 70 science textbooks have to say about scientific method.
Some readers advised me to read the work of Karl Popper, who championed a falsificationist method. (Falsification refers to attempts, by experiment or observation, to show that a theory is false, rather than attempts to verify it as true.) I have, and I wrote about it in “Of Two Minds” as well as in this essay, “Elimination, Correction, and Popper’s Evolutionary Epistemology,” published in International Studies in the Philosophy of Science.
One last point: Many of those who have simply dismissed philosophy (and poetry and other nonscientific areas of inquiry and expression), including some prominent scientists, have done so without displaying any evidence that they’ve ever worked through what they’re criticizing. Scientists often react strongly when their work is criticized by those who know very little about science, often with good cause. This is a two-way street. It does not seem wise for those who are unwilling or unable to work through challenging philosophical theories (including theories of scientific method) to simply dismiss them all. Where’s the objectivity in that?