Science and retrospective coherence

Thomas Kuhn’s The Structure of Scientific Revolutions - a justly famous book on the nature of science - introduced the term “paradigm shift” into the study of the history of science and thereby into our common discourse. It’s one of those works that everyone talks about but - it seems - few have read: including, sorry to say, me, until this last few weeks.

I read it back-to-back (more-or-less) with Paul Feyerabend’s Against Method, which covers the same ground, but with much greater emphasis on the anarchic, non-methodical practice that Feyerabend places at the centre of knowledge, a school of thought gloriously named Epistemological Anarchism.

Both Kuhn and Feyerabend talk at length about Galileo and his role in bringing about acceptance of the Copernican view of the cosmos. Both stress that at the time of it’s development and into Galileo’s time, both the old and new cosmology accounted equally well for the “observed facts” - also fascinating in Feyerabend’s account are stories of the difficulty Galileo’s contemporaries had in understanding the visual evidence of telescopes. There was no developed theory of otpics; Galileo’s instruments must have introduced distortions and other visual artefacts, and consequently there was a very real debate about what could be interpreted from what was being observed. Galileo’s assertion to some of his critics that he was on the point of publishing such a theory was at best wishful thinking.

I like Feyerabend’s description of Galileo’s arguments for the heliocentric view. Underlining the fact that to effect a revolution, (rational) arguments will not suffice, he notes

.. Galileo’s utterances are indeed arguments in appearance only. For Galileo uses propaganda. He uses psychological tricks in addition to whatever intellectual reasons he has to offer.

It’s salutary to look back at these episodes in science and realise that it wasn’t - and has never been - the case of one theory calmly replacing another, through experiment, observation, agreement. Looking back from the point of view of a new paradigm (and particularly in science, where the textbooks and teaching of the body of knowledge rapidly adapts to a new world view) it’s all to easy to ignore the reality of what happened, and what’s more the value in thinking outside a paradigm - indeed, without this paradigm change is clearly impossible. Both books are great counterpoints to our human tendency to impose pattern on our experience - retrospective coherence is a widespread trait, whether we’re trying to understand iterations, projects, relationships, history…

2 Responses to “Science and retrospective coherence”

  • Vasco Duarte responded:

    Indeed retrospective coherence is one of the worst enemies of agile teams trying to retrospectively assess their performance and trying to improve. The other enemy is the Halo Effect. The Halo Effect explains why a retrospective after a successful sprint yields much less things to change than a retrospective after a sprint that is considered “failed”.

    This happens indeed even if the “successful sprint” had inbuilt tremendous problems that should be addressed. THe problem is that we paint the past white or black based on the “present feeling”, hence the importance of collecting data and judging past performance based on that data, not based on just intuition or memory.

  • David responded:

    Good point on the Halo Effect. We’re often unaware and unwilling to admit how inaccurate our perceptions and recollections can be - here’s a recently documented example of just this:

    One of the most telling points in Kuhn’s elaboration of paradigm shifts is that different paradigms often disagree about the world, to the extent of what are deemed “facts” about it.

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