"Patterns of Discovery" by Norwood Russell Hanson

Hanson starts by undermining claims the science is objective by showing that visual illusions prove that "seeing is a 'theory-laden' undertaking" (p 19): two biologists looking at the same slide might disagree as to whether they are seeing an artefact of the staining process or an organelle. He then claims that this undermines the hypothetico-deductive model of science as popularised by (for example) Karl Popper in Conjectures and Refutations. At the same time he disagrees that the creation of a hypothesis is some sort of magical act of creativity:

"The initial suggestion of an hypothesis is very often a reasonable affair. It is not so often affected by intuition, insight, hunches, or other imponderables as biographers or scientists suggest." (p 71)

Unfortunately he seems to be light on the evidence for this point. I would offer the mass of evidence accumulated by Lowes in The Road to Xanadu when explaining the sources of inspiration for Coleridge when writing the Rime of the Ancient Mariner.

He then talks of different types of explanation laying particular stress on the 'abduction' or 'retroduction' of Peirce which Hanson suggests is the same as Aristotle's 'apagogy'.

He also points out that: "some events need less explaining than others" (p 95); as good a justification for Ockam's Razor as I have seen.

He shows how the laws of physics may start out as "empirical generalizations" but they can "graduate to being 'functionally a priori'" (p 98) in the same way that a legal judgement in one case can become a precedent for another.

He suggests that a theory is "an intelligible, systematic, conceptual pattern for the observed data. The value of this pattern lies in its capacity to unite phenomena which, without the theory, are either surprising, anomalies, or wholly unnoticed." (p 121)

In a moment that was stunningly exciting for me he showed why all electrons must be identical: Born showed that the electric field strength inside an electron must rise to a singularity and since only one kind of singularity is possible therefore all electrons must be the same. (p 135)

This short book was an immensely readable (and quaintly old-fashioned, it was written in 1965 and has endearing mannerisms like referring to Heisenberg as "Professor" Heisenberg) journey through a mall portion of the philosophy of science and deserves to be better known. May 2016; 158 pages