A theory, necessarily an abridged account of reality, ideally identifies elements that capture and represent all of the most effective forces generating social processes, events and patterns of conduct. Theories sketch out an analytical and explanatory route for scientific wayfarers, marking the terrain through which they will pass and pointing out what to observe and measure. That is to say, the journey is a consequence of the specific lens and compass involved. Someone else could pass along the road and see other important sites and landmarks if armed with a different theory.

Over the twenty years since Schatzki, Knorr-Cetina, & Von Savigny (2001) announced a “practice turn in contemporary theory,” theories of practice have gained significant traction through many empirical applications and explanatory accounts. This special issue implies that, on balance, practice theories provide good guidance, but systematically omit critical information. In response, the editors define their mission as “contaminating” practice theories. My dictionary defines the verb to contaminate as “to defile by touching or mixing with; to pollute; to corrupt; to infect.” These are strange objectives; to seek to contaminate knowledge sounds malevolent. The noun, contamination, has a more positive variant, “the blending into one of several stories, legends or plots.” Blending theoretical approaches is not necessarily a sinister activity, for Sociology rarely benefits from pure theory. Supplementing the stories woven by practice theory with others, through new applications testing its boundaries and limits, promises much.

Sociology does not live through facts alone. An explicit and sustained addressing of theoretical issues helps counteract an ever proliferating and perhaps stifling empiricism. We need greater clarity, explicit working definitions of key concepts and more fitting together. Most of the theoretical improvisations in this collection attempt to marry specific versions of practice theory — originating with Reckwitz, Schatzki, Shove, Pantzar and Watson, and Spaargaren (the decision as to which is rarely discussed or justified, c.f. Nicolini, 2012) — to derivations from new materialism, Actor Network Theory, Material Culture Theory, Science and Technology Studies, Pierre Bourdieu, and circuits of culture. The concepts added are heterogeneous. They mostly work well enough in the context of the specific topics to which they are addressed. If you want to understand the role of reverse vending machines (Giardullo, 2019), then you probably need concepts whose focal point is machines, their design and their functioning. If you seek to grasp wine-tasting (de Benedittis, 2019) it would be remiss not to notice the presence of glasses and bottles but probably better to concentrate on eyes, tongues and noses.

Most of the essays are not so much abstract critiques of theories of practice as modifications directed towards enhancing the explanation of specific substantive activities. The applications are often revealing, insightful and intriguing. The three papers allocated to me address practical, instrumental and commercial activities: cooking (by professional chefs), wine-tasting and fashion modelling. In my view, occupations are among the easiest types of activity for practice theory to analyse. In the office, the factory or the restaurant, freedom is limited; there are positions of power, people in occupational positions are obliged by others further up a hierarchy, and by virtue of the competition with peers, to carry out activities within certain parameters. Despite variability in performances due to differences in competence and technique, in adaptability, in inclination and aptitude, in embodied physiological capacity, etc., practitioners follow similar scripts. Perhaps therefore this type of scientific object requires fewer supplements.

Paolo Volonté (2019) offers a relatively straight-forward application of the theory of practice to fashion modelling. He emphasises inertia, routines, embodiment, the entanglement of performances and practices, habitat and convention. Using illustrations and demonstrations founded upon the most detailed ethnographies available (most notably Mears, 2011), he offers a fresh angle on the tyranny of slenderness and the specific techniques of the body which define walking the catwalk. The interpretation of key features of modelling is excellent, but involves very little blending. Perhaps the account might have benefited from some further exploration of themes within political economy, but it presents a very convincing account of how some very puzzling ways of acting are perpetuated.

On the basis of participant observation as a professional expert, Mario de Benedittis describes the procedures involved in wine-tasting. He extracts seven analytic dimensions from Andreas Reckwitz’s (2002) theoretical essay — “1) bodily activities; 2) mental activities; 3) materials; 4) spaces; 5) background knowledge and know-how; 6) emotions and motivational knowledge; and 7) language and meanings” — which he uses to describe professional practice. Importantly, these elements could be applied to many other domains of practice. He attributes suitable importance to bodies and instruments, but combines them with the affordances of relative social positioning and social privileges of practitioners. His persuasive account contains the necessary concepts for a thorough yet analytically economical description of crucial features of the activity. It is less a matter of what the materials do than how the interdependence of things and people results in particular ways of doing a job and making judgements about aesthetic quality. De Benedittis’s principal modification to a core practice theory framework consists in adding Bourdieusian notions of habitus and positioning within fields to explain variations in practice.

Lorenzo Domaneschi (2019), by contrast, very ambitiously traverses many theoretical patches — Poulain on the food space, Bennett and new materialism, Wilhite on distributed agency, Gherardi on sociomaterialism, Schatzki and Bourdieu. To my mind, this results in overload and risks confusion by blending too many diverse and probably incompatible ingredients. I am not convinced that the food space, the theoretical axioms of new materialism and the analysis of symbolic power can be aligned intelligibly. A problem arises with blending if a large and fragmentary array of concepts from discrepant origins come to obstruct detailed understanding and explanation. I therefore infer that blending is most successful when governed by careful addition and melding of sympathetic ingredients, often in relatively small quantities, and driven by specific explanatory purposes.

Overall, practice theory comes out of its interrogation in relatively good health. If we are looking for strong and versatile theory, it can be a good place to start. Proposed corrections are mostly sympathetic, implying that, despite significant differences within the group, practice theories have enough in common to constitute a viable and distinctive approach. There can be no doubt that they occupy a different bed from rational action theory or functionalism. Achievements include showing that investigations led by practice theoretical approaches tell us different things about activities than do alternatives. The papers that I examined closely make some very interesting and distinctive observations about the activities of wine-tasting, fashion-modelling and cooking, thereby producing very effective analyses of particular practices. I certainly take away an improved explanation of why fashion models look too thin and walk funny.

The normal approach to theorising is to identify the limitations of a given theory and to advance means for dealing with its omissions or partialities in its own terms, rather than to blend one with another. Should we modify or contaminate? Does blending enhance or detract from practice theory? These papers show that features of different approaches or traditions can be successfully brought together to demonstrably improve analyses of particular situations or activities. Blending however occurs to different degrees. Selecting appropriate supplements seems conditional upon precisely what is to be explained. The temptation to put too many ingredients with little mutual affinity into the pot has to be resisted.