The merits or otherwise of astrology have been subject to much discussion recently, resulting in attacks that have been critiqued by Rebecca Higgitt, amongst others. The problem, according to Higgitt, is that astrology is “rubbish” but not because of the astrologers’ knowledge (or otherwise) of astronomy, which has been the subject of derision. Since some astrologers do understand precession, for example, this focus on astronomical proficiency is the wrong way to object to astrology, serving only to annoy them (which may be an end in itself for some). Such an approach also provides astrologers with opportunities to gain credibility if they can demonstrate sound knowledge of astronomy and it may fail as a rhetorical strategy if the ridicule prompts believers in astrology to become intransigent and less likely to heed criticism (although this, again, may be an end in itself - a self-fulfilling “rubbish” astrology that never develops). In this context, it is interesting to consider the views of some philosophers of science who wrote on astrology and in this entry I look at the treatments of Popper, Kuhn and Feyerabend, not least because all three used astrology to make philosophical points about science.
For Popper, astrology was the prime example of pseudoscience and was precisely what a successful demarcation criterion should be able to exclude from science. The problem that he identified and sought to capture, through his emphasis on testability, was his insistence that astrologers are not interested in the possibility of their claims being falsified, such that any failures can be accounted for without danger to the overall theory:
Astrologers were greatly impressed, and misled, by what they believed to be confirming evidence - so much so that they were quite unimpressed by any unfavourable evidence. Moreover, by making their interpretations and prophecies sufficiently vague they were able to explain away anything that might have been a refutation of the theory had the theory and the prophecies been more precise. In order to escape falsification they destroyed the testability of their theory. (Conjectures and Refutations, pp48-49)
It is probably fair to say that this view of astrology remains popular today and is the one typically objected to as “rubbish” or fundamentally not science. Popper did accept that astrology had played a role in the history of science, noting for example the disagreement between Galileo and Kepler on the role of the moon’s influence in explaining the tides (both men also casting horoscopes for others). However, Kuhn argued that Popper’s characterisation of it was unfair: “[n]ot even astrology’s most convinced and vehement exponents doubted the recurrence of such failures” (see Kuhn’s Logic of Discovery or Psychology of Research? in Criticism and the Growth of Knowledge, pp8-9). In Kuhn’s account, astrologers were well aware of the epistemological difficulties confronting them, such as changes to the configuration of stars and planets, the imperfections of astronomical tables and the fact that most people did not know the time of their birth with any degree of precision. He complained that it is anachronistic to dismiss these as question begging because they were understood as limitations by astrologers; only afterwards, when astrology joined the ranks of pseudoscience, did they become examples of how astrologers would disingenuously account for failures.
Kuhn went on to claim that astrology is not a science but “a craft, one of the practical arts”. A shared theory of astrology was
… adequate only to establish the plausibility of the discipline and to provide a rationale for the various craft-rules which governed practice. These rules had proved their use in the past, but no practitioner supposed they were sufficient to prevent recurrent failure. A more articulated theory and more powerful rules were desired, but it would have been absurd to abandon a plausible and badly needed discipline with a tradition of limited success simply because these desiderata were not yet at hand. [Astrologers] had rules to apply [but] they had no puzzles to solve and therefore no science to practise. (Logic of Discovery or Psychology of Research?, pp8-9)
This, then, is Kuhn’s criticism of astrology: although failures existed and were accepted, they could be explained within the tradition and hence did not give rise to puzzles that needed to be solved. The epistemological problems noted above were known limitations but were not and could not be recast or used to revise the tradition. Kuhn thus corrected Popper’s limited appreciation of what astrologers historically did and pushed the problem to another level, according to which the issue is not what astrologers do but their inability to improve on it by recognising restrictions on development and trying to solve problems.
To see where Kuhn may have missed something, I now detour to look briefly at his notion of normal science. Feyerabend objected to Kuhn’s characterisation of normal science via the activity of problem solving, arguing that “[e]very statement which Kuhn makes about normal science remains true when we replace ‘normal science’ with ‘organized crime’.” Indeed, he claimed that organized crime could be understood as “puzzle-solving par excellence“, complete with “outstanding individuals, such as Dillinger, [who] introduce new and revolutionary ideas” (see his Consolations for the Specialist in Criticism and the Growth of Knowledge, p200). This criticism was obviously a reductio, which Feyerabend was fond of employing.
Feyerabend further argued (p207) that Kuhn’s own discussion of how paradigms are overthrown (i.e. via the help of alternatives (proliferation) and the enlargement of existing anomalies) does not permit a temporal separation of normal and revolutionary activity. If both tenacity and proliferation are important then we have no reason or obligation to wait - to first engage in a period of normal science - before we begin proliferating theories. Feyerabend therefore concluded that
… it is not the puzzle-solving activity that is responsible for the growth of our knowledge but the active interplay of various tenaciously held views. Moreover, it is the invention of new ideas and the attempt to secure for them a worthy place in the competition that leads to the overthrow of old and familiar paradigms (Consolations for the Specialist, p209).
Kuhn’s response (Reflections on my Critics, also in Criticism and the Growth of Knowledge) misread this. Having defended his prescription that “in the absence of an alternate mode that would serve similar functions, scientists should behave [according to Kuhn's model] if their concern is to improve scientific knowledge”, Kuhn claimed that both Feyerabend and Popper “find menace in the enterprise” and quoted Feyerabend to the effect that it is “liable to corrupt our understanding and diminish our pleasure” (p237). However, Feyerabend actually wrote this (in the form of a question) about his own “proliferation+tenacity” model (p209; see also the previously linked entry at this blog). He had posed the question after noting that “inventing goes on all time” (i.e. proliferation) and that the “change of attention does not reflect any profound structural change (such as for example a transition from puzzle solving to philosophical speculation and testing of foundations). It is nothing but a change of interest and of publicity.” For Feyerabend, normal science therefore does not exist: his own model describes how scientists actually behave (as opposed to how we say science occurs post facto) and the promotion of normal science or science as puzzle solving actually constrains science, along with the likelihood of revolutionary activity, because it fails to promote the need to immediately and of necessity begin proliferating theories.
Returning again to astrology, Feyerabend complained separately (see The strange case of astrology in Science in a Free Society) about the “Statement of 186 leading Scientists” against astrology in the Sep/Oct 1975 issue of the Humanist. For Feyerabend, astrology
… inherited interesting and profound ideas, but it distorted them, and replaced them by caricatures more adapted to the limited understanding of its practitioners. The caricatures are not used for research; there is no attempt to proceed into new domains and to enlarge our knowledge of extra-terrestrial influences; they simply serve as a reservoir of naive rules and phrases suited to impress the ignorant (p96).
Feyerabend’s criticism was that this lack of development was not the objection raised by the 186 leading scientists: instead of lamenting the stasis of astrology, they focused on its basic assumptions and indeed did so in ignorance of astrology (even later admitting a lack of knowledge of it). Moreover, they insisted on the power to declare it false by decree, which violated the most basic lesson from the history of science that even apparently hopeless ideas might one day be developed and shown to be worth considering. The real issue, for Feyerabend, was astrology’s failure to accord with his model: although astrology’s exponents exhibit tenacity, especially in the face of difficulties, there is no attempt to enhance the defence of this tenacity and no proliferation of alternatives.
In summary, the philosophical problem for astrology is thus not that it can always explain failures (Popper) or that it does not attempt to solve problems (Kuhn) but instead that it has stagnated (Feyerabend) - assuming that this progression in criticisms is fair, of course. Notice that, for both Kuhn and Feyerabend, this is not a final verdict: if astrology can become problem solving or - better - if it can strengthen its arguments while proliferating alternative theories, it might be possible to eventually reassess it. However, excoriating astrologers or calling their discipline “rubbish” is perhaps unlikely to encourage such an improvement in matters.
Popper, K. (2010 ) Conjectures and Refutations. Abingdon: Routledge.
Lakatos, I. and Musgrave, A. (Eds.) (1970) Criticism and the Growth of Knowledge. Cambridge: Cambridge University Press.
Feyerabend, P. (1978) Science in a Free Society. London: New Left Books.