Scientific realism and inference​ to the best explanation

17 March, 2018 at 09:14 | Posted in Theory of Science & Methodology | 11 Comments

In a time when scientific relativism is expanding, it is important to keep up the claim for not reducing science to a pure discursive level. We have to maintain the Enlightenment tradition of thinking of reality as principally independent of our views of it and of the main task of science as studying the structure of this reality. Perhaps the most important contribution a researcher can make is to reveal what this reality that is the object of science actually looks like.

darScience is made possible by the fact that there are structures that are durable and largely independent of our knowledge or beliefs about them. There exists a reality beyond our theories and concepts of it. It is this independent reality that our theories in some way deal with. Contrary to positivism, I would as a critical realist argue that the main task of science is not to detect event-regularities between observed facts. Rather, that task must be conceived as identifying the underlying structure and forces that produce the observed events.

Instead of building models based on logic-axiomatic, topic-neutral, context-insensitive and non-ampliative​ deductive reasoning — as in mainstream economic theory — it would be much more fruitful and relevant to apply inference to the best explanation.

People object that the best available explanation might be false. Quite so – and so what? It goes without saying that any explanation might be false, in the sense that it is not necessarily true. It is absurd to suppose that the only things we can reasonably believe are necessary truths …

People object that being the best available explanation of a fact does not prove something to be true or even probable. Quite so – and again, so what? The explanationist principle – “It is reasonable to believe that the best available explanation of any fact is true” – means that it is reasonable to believe or think true things that have not been shown to be true or probable, more likely true than not.

Alan Musgrave


  1. Even when identifying the underlying structures and forces of observed events, which would have to be detected to be criticized, the issue is whether to accept an evidence based hypothesis or to reject such an hypothesis.

    What is at issue here in the ‘inference to the best explanation’ is whether a falsified hypothesis is recognized as significant or whether some degree of justification of an hypothesis test is given as the basis for the inference.

  2. “the main task of science is not to detect event-regularities between observed facts. Rather, that task must be conceived as identifying the underlying structure and forces that produce the observed events.”
    It is true that scientific progress requires imaginative new ideas. The sources of such ideas appear to be very varied and rather mysterious.
    However, it the need for great new theories does NOT imply that empirical evidence is not equally essential – evidence is required to justify theories. Moreover, the hard graft of gathering evidence and looking at event-regularities may can be a major inspiration for new and better theories.

    For example, Darwin spent decades finding extensive evidence showing regularities/patterns between the variety of species and their environments. This led to the development of his theory of evolution. Even more powerful was his evidence regarding the improbability of alternative theories.
    When all other possibilities are extinguished, the probability that the sole remaining explanation is correct approaches unity.

    • Are you aware that biology is going through (actually has been since the rise of modern developmental biology) a theoretical revolution as we speak? Evo-devo and developmental biology has undermined many assumptions in the Modern Synthesis that were taken for granted. Epigenetics raises old ideas that were once dismissed by early classical neo-Darwinian theories and the Modern Synthesis. Biology is going through a new Re-Synthesis to integrate these findings. Walls in my library are filled with graduate textbooks on this subject but so few are even aware of these changes in theoretical biology. And of course, the Re-Synthesis is unfinished so it in many ways is similar to mainstream economics vs. heterodox economics and many of the same conceptual and philosophical issues apply.

  3. Lars, this analysis applies to the claim of “first principles” and “fundamental axioms” required in such “first principles” claims too, correct?

  4. I am sympathetic with the explanationists’ principle ‘It is reasonable to believe that the best available explanation of any fact is true’, but as a pedant would rather say ‘It is reasonable to believe that the best available explanation of any fact is true to the fact within their proper context‘, while it is a matter of rare judgement as to what the proper context is. I agree with William James that people tend to think it will be their entire future experience, that nothing essential ever changes. But physicists do sometimes come up with a radical new experiment, and financiers do sometimes invent some radical new instrument, thus by design or negligence breaking the old context.

  5. Science is made possible by the fact that there are structures that are durable and largely independent of our knowledge or beliefs about them.
    I do not see how you can hold such a view and do a social science. The underlying structures and forces of society consist of people’s knowledge and beliefs about the society in which they live. The reflexive nature of social reality is inherent to the phenomenon of society. Economists may well prescribe, design and manage the institutions they develop knowledge of. Money or a central bank may be durable structures of a political economy, but they are human inventions and they work to organize society by means in large part of economist’s knowledge and beliefs about them.
    . . . I would as a critical realist argue that the main task of science is not to detect event-regularities between observed facts. Rather, that task must be conceived as identifying the underlying structure and forces that produce the observed events.
    As a pragmatist, I could affirm your belief. A naïve search for “event-regularities” risks presuming as truth the fallacy of post hoc, propter hoc. But, my core presumption about the world is also not that it is “objective”, structural or durable. My core presumptions are, first, that the world is singular and, second, that the world is a logical place. So, a logical place and the only place: I presume that you and I inhabit the same world and if I devise some objective measure of that world, you can use that same method to affirm that our common world is, in respect of the common measure, “that way” and no other, despite our different subjective experiences and individual points of view. Critical method is thus at the center of any project to overcome the narcissism of subjective experience to determine and communicate among ourselves some truths about the singular world we inhabit.
    It is in the implications I draw from embracing the presumption that the world is a logical place that I feel I may depart from Prof Syll’s preferred views most sharply. I would not presume that reality manifests either structure or durability as properties, except insofar as logical necessity entails structure or durability in the system mechanics of reality’s order. Science, in my view, is the business of discovering the orderly systems of the world as mechanisms: structure and forces producing the observable events or phenomena, tied together as systems bound by logical necessity, aka mechanisms. Newton discovered a mechanism in the elliptical orbits of the planets; Darwin discovered a mechanism in natural selection.
    It seems to me that we are precluded from directly observing the operation of logical necessity in the cause-and-effect of any system’s mechanism, as Hume pointed out long ago. We cannot “see” cause-and-effect when one billiard ball strikes another, and Newton’s laws of motion play out in angle and spin and momentum, however long we stare at the table. We must imagine the unseen mechanism’s logic, confident that reality is bound by logic and not the whims of capricious gods. We must have a theory, a way of thinking that develops and proves the logic of the relations that make up the order of a system.
    It is in this essential act of imagination, disciplined by logic, that theoretical analysis plays its indispensable role. I am not hostile to deductive logic applied in theoretical analysis. I do object to confusing analysis with description or measurement or knowledge of what is. I object to confusing geometry with map-making, a fatal fault of neoclassical economics. Analysis tests possibilities; it can never prove a fact.
    For a pragmatist like myself, the test of truth by method is seeing what works: we test not our theories but the world and its mechanisms, by operating those mechanisms. We prove our physics as fact by constructing machines and operating those machines.
    If inference to the best explanation is constructing in its “explanation” a kind of machine for this factual testing of the world, I am in sympathy. I can understand “explanation” as a kind of narrative account of the alleged machine’s operation.
    I am not so much in sympathy with talk of “abduction” as an analogue to the procedures of logic or math, complete with notation. This strikes me as wholly misleading in every implication, including especially the arrogant bootstrapping of observed facts into a theory without worrying overmuch about introducing logic. Try it, if you must, I say, but I do not think you have a working machine capable of the work assigned in this version of IBE.

    • The structures which are in place are durable and human inventions, but it is a complex of structures or a structural complexity where a myriad of decisions, of “plastic controls” as Popper calls them, occurs to given the overall impression of durability or effectiveness.

      The role of subjectivity is overlooked. Not only must the individual’s voluntarism get addressed, but the relation of structural knowledge and mechanisms cannot merely relate to organisms or populations/groups or “the world,” but must take into consideration subjectivities. Since system thinking isn’t complex enough to do that, there are serious inequalities, and not merely perceived inequalities although system complexities have the tendency of concealing their consequences and their unintended consequences.

      The point of abduction as the generation of hypotheses, or guessing, is to improve the system, or quality of life, or problem-solving. One method of abduction is to form new hypotheses on the basis of failed hypotheses, or a method of continuously improving one’s hypotheses. Another method is to look to the arts for imaginative depictions and frame hypotheses from the conjectures in works like novels, films or scripts, biographies and memoirs, etc., and to test those scientifically.

      The main idea is that durable structures, logic and reasoning, should not be considered as complete or sound at this time, although some ‘mechanisms and theorems are complete and sound for the most part. Natural selection is posited as a process of eliminating genes or memes that do not work, however natural selection does not generate anything, it only eliminates. Darwin posited sexual selection as a positive selecting mechanism where the results of natural selection are poised to generate new structures, or organisms, or hypotheses. We need a kind of sexual selection in science to select those hypotheses which have survived and generate their results.

      The obstacle is that our durable structures like traditions, cultural ways of life, ethnocentric folkways, religious beliefs, and many “scientific” theories and practices are like vetoes for the processes of generating, testing and implementing hypotheses. Within science and the philosophy of science, abduction tries to explain where hypotheses come from, induction and deduction on the processes of inference and falsification, all three work together to arrive at theoretical solutions to problems. There are other possible solutions which may give utilitarian results but at the expense of the subjectivity of others.

      • If you want to say, “guess”, then say, “guess”. I have no problem with guessing, but then what?
        In a comment on an earlier post referencing IBE, I asked if there was a best explanation of what is an explanation. I was serious in asking the question.
        I think we should be interested in epistemology before methodology: sound methodology will follow from sound epistemology. These discussions stay abstract and they should not; in my view, we should get down to cases. Abduct away, but let the first object of study be study itself. Take some exemplary of (scientific) knowledge and explain the explanation: show how theory figures in the establishment of fact, if that is how it seems to have worked, or show how fact has vindicated some guess. Show something.

  6. I can’t read everything so I can’t be expected to respond to your earlier remarks if they are not in the present thread!

    The question pertaining to abduction is about the origin of hypotheses. If we say trial and error is a sort of basic method, where does the idea of a particular trial come from? It may come from a synthesis of evaluation of previous trials or hypotheses with their mix of partial success and failures, or from a literary imaginative source – which should not be scoffed at, or at a guess which is some range between logical consequence and wild!!

    If you are asking about what an explanation is in terms of science then certain elements should be considered: pertinent evidence, reasons and logical conclusions or consequences, inference, reasoning about the connection between an assertion/claim and the evidence or data considered relevant and an anticipation of possible objections and criticisms. All of this is a part of theory – a theory is an explanation of an event or type of event.

    • I think there’s an element of “we know knowledge when we see it” or discover it and that we should not be confident that we anticipate its shape or form in advance. I don’t think the precedent of Newton’s Laws of Motion helped Darwin much — the so-called Law of Gravity, Darwin’s Natural Selection, Einstein’s Special Theory of Relativity, Little’s Four Theorems of Queuing Theory, the historical methods of modern Geology — these are just a few examples where we scored a scientific breakthru that opened up new domains for effectual “explanation”. I think we should study such examples, to see how deductive reasoning and evidence sort themselves out in the composition of what we may agree is successful scientific work. That’s all.

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