Sir

In the days of sound-bite epistemology, I should not be surprised thatGottfried and Wilson1 characterize my book, Constructing Quarks, by two short and decontextualized quotations from the last two paragraphs of a text which is 415 pages long (not counting a 43-page bibliography, most of it citations to the high-energy physics (HEP) literature)2. One unfortunate consequence is that readers might imagine that there are no argumentative connections linking my “preposterous conclusions” to the historical substance of my book — which Gottfried and Wilson concede “displays a solid command of the developments that led to the Standard Model” and covers the “transition from the ‘old’ to the ‘new’ physics . . . very well indeed”, and which Gottfried has elsewhere generously described as “a superb account”3. I do have some arguments, however.

Gottfried and Wilson assert as self-evident that (a) the old and new physics were of “objectively unequal merit”, implying that (b) this was the reason that the latter eclipsed the former. In regard to (a), I show in Constructing Quarks that this was a matter for legitimate dispute. One can argue that the standard model fits some philosophical criteria for theory-choice better than the theories and models of the old physics, but conversely one can argue that the old physics had the merit of explaining almost all of the phenomena that appear in the HEP laboratory. New-physics data are terribly rare, and become visible only when an overwhelming ‘background’ of old-physics events is excluded from the analysis. Point (b) I believe to be historically untrue. In my historical research, I interviewed more than a hundred leading high-energy physicists and studied the published and unpublished literature extensively, and, in all honesty, that evidence did not persuade me that “objective merit” (as defined by Gottfried and Wilson) was what induced most physicists to move from one domain of knowledge and practice to the other. More positively, the same evidence did persuade me that such shifts could be easily understood in terms of what I called the dynamics of practice, relating research trajectories to the prior expertise of the physicists involved, symbiotic circuits of experimental and theoretical practice and so on. Much of Constructing Quarks is devoted to exemplifying that point; it is one of the links from the history to my “preposterous” conclusions; and neither Gottfried and Wilson, nor any other particle physicist, has ever disputed the adequacy of that aspect of my book.

The other critical thread that runs through Gottfried and Wilson's essay concerns the issue of prediction in science. They accuse me of assuming “the power to stop the clock at an arbitrary point, thereby ignoring subsequent evidence as to whether some bandwagon fell off the cliff or stayed on track”. The term bandwagon does not figure in my interpretive lexicon, but there is a grain of irrelevant truth to that quotation. I handed over the final manuscript of Constructing Quarks in mid-July 1983 (immediately after my daughter Lucy was born), so I could not, for example, follow the story of the discovery of the W and Z particles very far (though I did my best: see the long footnote 44, 379-380, dated July 1983). But I did follow similarly important stories that had more-or-less run their course before paternity took over — scaling, the weak neutral current, charmed particles (see also my other publications expanding on these topics: copies available on request). And for those discoveries I argued in detail, again, that my model of the dynamics of practice fitted the historical evidence better than simple assertions that ‘we got it right’. If Gottfried and Wilson want to challenge my specific accounts and interpretations of those events, I would be happy to argue with them. Failing that, it seems reasonable to regard their invocation of the Ws and Zs as a red herring.

One last remark. Gottfried and Wilson read into Constructing Quarks the sceptical message that “science is only a communal belief system with a dubious grip on reality”. But the message was not sceptical: I defy anybody to find textual warrant for either the “only” or the “dubious” in that quotation. Like many scientists (and philosophers), Gottfried and Wilson assume that Constructing Quarks asserts the opposite of their stock image of science, but this is just a mistake. Over the past fourteen years I have explored more deeply the engagement of science with its object, the material world; for that, see my latest book, The Mangle of Practice4. But nothing there contradicts what I wrote in Constructing Quarks.