With _Methodological Pluralism_ and _Critical Systems Thinking_ dominant amongst scholars in the systems sciences for many decades, [Zhichang Zhu](https://scholar.google.com/citations?user=pXpqv38AAAAJ&hl=en) looks to Thomas Kuhn's work on _scientific paradigm_ as later superseded by an _evolutionist_ perspecitve on _proliferation of specialties_.
Methological Pluralism is theory, and Mixed Methodology is practice, clarified in a footnote. >  There are various labels applied to the ‘combined-use methodologies’ pursuit: Midgley (2000) labels it Methodological Pluralism, Mingers (1997) Multi-paradigm Multimethodology, Jackson (2000) Coherent Pluralism, Gregory (1996) Discordant Pluralism, Zhu (2011) Mixing- methodology, and so on. As this article focuses mainly on theorising, Methodological Pluralism (MP) is chosen as the representative label; when it comes to practice, Mixing-methodology will be used since, in my understanding, the term suggests an ‘action’ inclination.
New contributions towards Methodological Pluralism seems to have stagnated, says Zhu, while adoption of Critical Systems Thinking and Critical Systems Practice in the wider management sciences has beeen limited. > Almost immediately after MP/CST started, a ‘meta-paradigm’ controversy exposed the trouble of the Paradigm-theoretic approach. The response, as it looks clear today, was more Paradigm talks (see later sections of this article). Since then, despite challenging voices, path-dependence effect continues to lock MP/CST theorising in a Paradigm-bounded, no-win battle. > *  For challenging voices see, for example, Bowen (1998), Keys (1997, 2006), Lane (2000), Ormerod (2006, 2021), Pidd (2004), Stacey (2007), Tsoukas (1992, 1993), Ulrich (2003), White and Taket (1997) and Zhu (2006, 2011). > And what does the prospect look like today? Signs are that MP/CST is stagnating: theoretical inquiry subsides, ‘with less intensity now’ (Midgley et al., 2017, p. 151), and practitioners no longer bother the Paradigm talk (Ormerod, 2020). Some may interpret this as the evidence of victory. To those who hold a ‘not yet’ assessment, it indicates that MP theorising reaches a critical point: fossilised along with the Paradigm mentality, or searching for alternatives to revitalise itself. > This article suggests an alternative. The alternative is drawn, perhaps to the surprise of the Paradigm talk advocates, from Thomas Kuhn. Amid great influence of his earlier revolutionist paradigm-shift thesis, Kuhn increasingly in his mature work emphasised scientific progress as proliferation of specialties that parallels biological speciation. It is this Kuhnian evolutionist perspective vis-à-vis the Paradigm-theoretic approach that, I would posit, shall better serve MP by depicting the increasing variety of methodologies as the outcome of deepened division of intellectual labour and the combined-use of which as enlarged human competence. > *  My intent with this present article is modestly to break the Paradigm shackle on MP/CST theorising by introducing a fuller appreciation of Kuhn's work to the OR/MS/Systems community. It should be reminded that, apart from Kuhn's, there are rich, useful resources available with similar concerns, for example, Hacking (1983, 1999), Rouse (1991, 1996), Fine (1986, 1991) and, of course, Rorty (1982, 1989, 1999). The pluralist, pragmatic world is much bigger than Kuhn's works and readers may explore more alternatives. Zhu was on the faculty of the University of Hull Business School, and thus interested not only in theory but also practice. He was active in conferences and publications of the [The Operational Research Society](https://www.theorsociety.com) in the UK.
## 2. The Paradigm Mentality
### 2.1 How it started > MP/CST was triggered by a debate erupted in the 1980s. By that time, unintended consequences of OR/MS projects in solving social problems accumulated, and new methodologies emerged, shaking the conventional status quo. This led some to question whether the discipline was destinating to a ‘Kuhnian crisis’ (e.g., Dando & Bennett, 1981). With their landmark paper now known as ‘SOSM’, Jackson and Keys (1984) entered the debate, positing (1) that each methodology is useful for solving certain type of problem, (2) that so long as we understand the strengths and weaknesses of various methodologies, we can match them with problem situations where they work best and thus (3) that diverse methodologies herald not a crisis but increased problem-solving competence. Subsequently, Jackson (1987) proposed a complementarist (vis-à-vis isolationist, imperialist and pragmatist) strategy for MP. This inclusive, optimistic vision made an instant impact and effectively set MP/CST in motion. [pp. 896-897] > [....] > It is a problem because ‘paradigm’ is not a standalone concept. In Kuhn's thesis, ‘paradigm’, ‘incommensurability’ and ‘paradigm-shift’ are logically coherent, mutually supportive notions, they are interrelated parts of an intellectual whole, each makes sense only in relation with others. We cannot just pick up one and wish the rest to go away. In the ‘crisis’ argument, all these Kuhnian concepts worked together towards that ‘crisis’ imagination, an imagination we may or may not like. > [....] > Nevertheless, MP/CST advocates were quick to frame OR/MS methodologies as being ‘inevitably’ ‘born into’, ‘developed from’, ‘underpinned by’, ‘based on’, ‘premised upon’, ‘depending on’, ‘adhering to’, ‘conceived in’, ‘closely linked to’, or ‘embody’, sociological paradigms à la Burrell and Morgan (1979) (hereafter B&M). So much so that Paradigm has since become, and still is, the lingua franca of MP/CST discourse, regarded as the guarantor of ‘critical systems thinking’ and ‘creative problem solving’. [p. 897]
## 3. Proliferation of specialties
In the SRBS article, sections under 3.1 appears as bullets. For readability, implied subsection numbering (e.g. 3.1.1, 3.1.2, ... 3.1.6) may help structure the ideas.
### 3.1 Kuhn's evolutionary perspective > In the very last pages of _The Structure of Scientific Revolution_ (hereafter _Structure_), Kuhn (1962/1970) introduced an analogy between biological evolution and scientific change. Over the following decades, Kuhn further developed this perspective, came to characterise success in science as a consequence of increasing intellectual specialisations. Kuhn promised us a book on his evolutionist turn, which is unmaterialised due to his untimely death. Among Kuhn's evolutionist insights, the following appear particularly useful to the MP/CST debate.  [p. 900] > *  The main references for this section are Kuhn (1990, 2000), Mladenovic (2017) and Wray (2011).
#### (3.1.1 Later Kuhn with specialities, rather than punctuated paradigm-replacements) > * In _Structure_, history of science is depicted as periods of normal science punctuated by paradigm-replacements through which persistent anomalies are sorted out. Whereas in Kuhn's later writings, forming new specialties is shown to be an alternative, indeed a usual, response scientists in a discipline make to anomalies. That is, in seeking for resolution of problems with which the discipline was unable to deal, new specialisaions emerge within, resulting in new-formed specialties. Each specialty allows a group of scientists to pursue the study of a narrower range of phenomena, ask more specific questions, innovate new conceptual and methodological tools, gain narrower but deeper knowledge and gradually accumulate distinctive expertise. As at the speciation-event nodes on the phylogenetic tree, scientific specialties can be seen as shoot-off branches. During the process, some of the old questions and competences die, some others survive, to be employed in a restricted domain. ‘It is by these divisions ... that knowledge grows’ (Kuhn, 1990, p. 9). [pp. 900-901] [....]
#### (3.1.2 Mature Kuhn with Lexicon) > * Kuhn's ‘paradigm’ and associated notions in _Structure_, whilst produced instant impact, generated conflicting interpretations. In his later work, Kuhn appeared to have learnt the lesson. At the places in the revolutionary model of notions ‘disciplinary-matrix’, ‘exemplar’ and ‘paradigm-shift’, now in the evolutionist perspective there are ‘lexicon’, ‘lexical structure’ and ‘lexical change’. > To the mature Kuhn, a lexicon is a set of taxonomic categories, or kind terms, such as cat, planet, actor, worldview, that are used to denote natural kinds, artefactual kinds, social kinds, and probably others, which are primarily count nouns. As each scientific community uses a distinctive lexicon for the study of a particlar range of phenomena, scientific communities are differentiated by the lexicons they use. [pp. 901-902] [....]
#### (3.1.3 Biological natural selection c.f. scientific revolution) > * Now what is lexicon meant to the individual vis-à-vis the community? Here, Kuhn made a further analogy between biological and scientific evolutions. In biology, the unit of natural selection is a reproductively isolated population whose members collectively share a gene pool; in the science case, the unit is the specialty, that is, a community of scientists who share a lexicon. [....] > It appears thus clear, to the mature Kuhn, that (1) members of a community possess individual lexicons, (2) individual lexicons must share the lexicon structure of the community and (3) what holds the members together is the community-specific lexicon structure. A further implication is that, when a critical mass of individual lexicons decouple with the community's lexicon structure, new specialties are likely to develop. [p. 902]
#### (3.1.4 Incommensurability between lexicons) > * Based on ‘lexical difference’, Kuhn reformulated the notion ‘incommensurability’, a notion concerned him so deeply over the 30 years since Structure. What is Kuhn's mature formulation, then? [p. 902] [....] [....] to the mature Kuhn, incommensurability between lexicons occurs because (1) there exist unshared categories and/or (2) the shared categories are used in different meanings. It is worth notice that in Kuhn's earlier revolutionary model incommensurability is meant to be diachronically between old and new paradigms, whereas in his later evolutionary perspective it is conceptualised to be synchronically between contemporary specialties: ‘I've only in the last few years begun to see its significance to the parallels between biological evolution and scientific development’ (Kuhn, 1990, p. 5). [....] [p. 903]
#### (3.1.5 Incommensurability as constructive to science advancement) > * Should incommensurability be overcome? In his later writings, Kuhn shed a positive light on the matter, claimed that incommensurability between specialties fulfils the constructive function as an ‘isolating mechanism’ which is imperative for science advancement. Just as physical barriers, like mountains or wide waterways, that aid speciation in the biological world, the isolation that results from incommensurability between specialties enables each of them to concentrate on its domain-specific research, allows local innovations to take hold without too much interference from neighbouring specialties. [....] > Kuhn did notice that contemporary scientific ventures increasingly demand interdisciplinary efforts. Yet, in Kuhn's view, that will not lead to unification of science but to further specialties that emerge at overlaps. There are consequences. [p. 903]
#### (3.1.6 Scientific changes sometiems revolutionary, sometimes biological speciation) > * A simplistic reading of Kuhn may lead to an impression that Kuhn was to replace the early revolutionary model with his later evolutionary perspective. That would be mistaken. According to recent research (e.g., Mladenovi c, 2017; Wray, 2011), Kuhn was of the view that not all anomalies and crises in science are resolved in the same manner. Sometimes scientific change takes a revolutionary form that replaces the discipline's long-accepted lexicon with a new one, whereas other times resembles the process of biological speciation by creating new lexicons. Kuhn showed us different patterns of change, and he would lead us to see the difference as being in focus and emphasis only. [pp. 903-904] > Thinking in terms of units of time as long as several centuries, Kuhn observed revolutionary changes from Aristotle to Newton to Einstein, whereas examining a synchronic slice across disciplines, Kuhn drew our attention to increasing specialisations as the important feature. In the end, the two accounts are ‘mutually enriching since they offer alternative explanatory frameworks for any philosophy of science interested in being able to adjust its historical focus as appropriate’ (Mladenovic, 2017, pp. 162–163). With deep intellectual roots in American pragmatism, Kuhn would have us to be open, pluralist, and responsive: which perspective to deploy should depend on the task, evidence and resources at hand. [p. 904]
> ... I would suggest, in Kuhn's spirit we can adapt his accounts by adding a third form of knowledge progress, a form that fits the PM purpose in OR/MS. That extended form I shall, following Kuhn's custom, call ‘scientific cooperation’, to be conducted by project-based teams (see Table 1). [p. 905]
> Working on a specific project usually within a limited time span, and hopefully with stakeholders as widely as possible, members from different specialisations temporarily come together, enlarge overlaps between their expertise cum methodologies, construct a temporary, purpose-built working lexicon, gear towards and compromise on pro- posals for action. Projects come and go, providing learning and socialising opportunities for those involved to improve knowledge, skill and social capital. Based on real-world experiences and the still-growing body of literature on project-based teams, for example those from neighbouring disciplines such as Strategy and Knowledge Management, well-designed research and training programmes shall, we can expect, greatly enrich MP theorising and practice in OR/MS (this will be the topic of yet another article). [pp. 905-906]
## 5. Conclusion > Methodological pluralism, particularly the CST version, once an open, promising movement in OR/MS/Systems, has gradually been highjacked by the Paradigm mentality; the consequence is stagnating in theorising and losing appeal to practitioners. It is time to adopt a strongly open, pluralistic, responsive approach, reflect on the Paradigm root metaphor and seek alternatives. To facilitate this urgently needed process, this article introduces a theoretic alternative which is drawn from Kuhn's ‘proliferation of specialty’ perspective. [p. 909] > At root, ‘responsive’ is a biological-evolutionary concept, and effective responsiveness over time demands the availability of sufficient, heterogenous alternatives not arguing for replacing ‘paradigm’ for ‘specialty’ once and for all. Rather, I am suggesting contingently deploying the ‘fitter’ alternative for responding to changing circumstances, tasks, resources and, most importantly, experiences and demands from the practical frontline. The paradigm-theoretic approach has made considerable contributions to the MP/CST movement, especially in the early years, and still has a role to play, particularly in pedagogical programmes. With this said, my here-and-now judgement is that the current Paradigm hegemony in MP/CST theorising must be questioned and choices be made based on open, sustained competition between alternatives. New alternatives, Kuhn's included, just like specialties, need space and time to develop, adapt, apply, test and compete, wherein lies the future of methodological pluralism theorising and mixing-methodology practice, in OR/MS/Systems and beyond. [pp. 909-910]
# Reference Zhu, Zhichang. 2022. “Paradigm, Specialty, Pragmatism: Kuhn’s Legacy to Methodological Pluralism.” _Systems Research and Behavioral Science_ 39 (5): 895–912. https://doi.org/10.1002/sres.2881 .