All theories are wrong but some are useful

Theory and Explanation in Geography (Yeung, 2023) offers exactly what the title advertises: a book about theory in geography. But what does it mean for a book to be 'about theory'? In this case, as expected, the contents are about theory, with interesting, structured, and extensive discussion of the theoretical foundations upon which contemporary human geography is built. The book's thesis, too, deals with theory, advancing an argument for the kind of theory human geographers should be producing – mid-level, explanatory theory that is socially and spatially contextualised and practical. At this point, if this were a traditional book review, I would add that Yeung's is a wide-reaching book about geographical theory, aimed expansively at the entire discipline. I certainly expect it to find a broad audience, especially among those seeking an overview of theory in geography or those who simply really enjoy reading books about geography and theory. But this is not that kind of book review.

There are other ways that Yeung's book engages with theory and, especially, theorisation, in human geography that stand out as particularly worthy of discipline-wide conversation. What characterises a theory, what purpose theory serves, and who gets to theorise are often unspoken but firmly – and, occasionally, harshly – policed in human geography. Although the identity of every sub-field of human geography is grounded in theory, it is also true that many would (and do!) point to others’ theory and say, yes, but that is not real theory. In our discipline – our journals, our hiring committees, our funding panels – there is perhaps no critique more damning than a determination that one's research is insufficiently theoretically framed (very often measured against someone else's definition of theory). For all we may blame methodological or epistemological differences for continued fractures in geography, the true culprit may be our varied definitions of theory and our failure to collectively appreciate diverse forms of theory and theorising. This is important. Theory both unifies and divides geography and, more prosaically, accomplishment in theory is one of our primary mechanisms for attributing disciplinary status. So we should talk about ‘doing theory’ in human geography and Yeung's book provides an excellent opening.

To start with, what is theory for? Yeung articulates a vision for what theory should be, but its purpose – why we theorise – is largely taken as given. ¹ The purpose of theory is important, however, as it helps elucidate the diversity of approaches to theory that we observe across the discipline. There is, I hope, broad agreement that, at its core, theory's job is to illuminate, if not explain, a phenomenon, experience, process, or outcome. In my sub-field of quantitative human geography, theory is explanatory. It unpacks the workings of relationships, outcomes, or processes and governs choices about data and methods (Franklin, 2023). More broadly, theory helps us tell a story about why things are the way they are. This is amply evident from Yeung's discussion. Feminism, colonialism, post-structuralism, or Marxism all (I believe) convincingly account for some share of the world's working. Reading Yeung, it is also evident that an additional purpose of theory is to place individuals and ideas in conversation with each other. Much of the book, in fact, is a exposition of specific ways in which people and ideas have been in dialogue with each other for a very long time. Illuminating or explaining a specific process or phenomenon, even if it was possibly an initial goal, does not appear to be the primary purpose of theory. Instead, it is as dialogue generator. Another, mundane, purpose of theory is to provide employment. It's a thing that many of us do because it is our job. Maintaining sufficient ongoing, generative, theoretical conversations helps motivate publications and build careers. I make this point not as a critique of certain kinds of theory, but to highlight that theory is no less susceptible to everyday academic pressures than analytical, applied, or any other type of human geography activity.

One of the true purposes of theory is to act as disciplinary infrastructure. Theory – however we do it – structures and supports our research, our interpretations of what we observe, and our engagement with the wider world. Theory also provides connections and communication lines within and across a heterogeneous discipline, and, within sub-fields, establishes communities of practice and a lingua franca. Theory is therefore essential disciplinary architecture. As such, it requires ongoing investment into its capacity to serve all human geographers, because we ignore shaky communication lines and foundational connections at our peril. In that light, Yeung's book can be seen as valuable infrastructural maintenance. O'Sullivan's (2024) recent monograph, which argues for conceptual and theoretical bridge-building between GIScience and human geography, is another useful example of recent infrastructural reinforcement.

Just as there is no one single type of essential infrastructure, neither is there any one type of essential theory. Yeung, but also Miller (2018), make a case for mid-level, or meso-, theory, but a strong discipline requires a variety of kinds of theory for maximum strength and resilience. Put plainly, there is no one type of theory that, alone, can serve to support an entire discipline. Instead, it's the interlocking connections of theories, macro, meso, and micro, that constitute robust theoretical infrastructure.

Infrastructural theory (and, per above, all theory is infrastructural) not only requires maintenance and investment, but also demands attention to other issues. For example, under what circumstances is new theory called for? How can we acknowledge the ways in which theoretical redundancy is valuable, highlighting diverse facets of a common phenomenon? How do we care for existing theory, not only within our own communities but across the discipline, as infrastructural maintenance? Wider societal tensions between ‘makers’ and ‘carers’ come to mind, often replicated within our discipline in ways that privilege the new over repair, evolution, and repurposing of the existing. Similarly, the ‘right to repair’ holds for theory, as well. My sense is that, within sub-fields of human geography, the right to repair is already well embedded in our practices. This is, indeed, a lens through which Yeung can be read: initial theoretical contributions that are continually iterated, extended, and repurposed for different contexts and situations. (We do this too in quantitative human geography!) As a discipline, we may, however, be less likely to extend the right to repair to others’ theory. As a quantitative human geographer, my general sense is that other sub-fields continue to assess us by the theory of two generations ago (Franklin, 2023), failing to allow for the same processes of conversation, evolution, and repair that they accord themselves and their own theory.

Yeung calls for a very particular kind of theory: adjacent to ‘grounded theory, dirty theory, minor theory, modest theory’ (2023: XIII). He argues for practical, mid-range, workhorse theory that explains, that exposes causal mechanisms, and that can be fruitfully applied in empirical settings. Good mid-level theory, for Yeung, leverages the peculiarities of local socio-spatial contexts and situations and it is normative – it not only explains but spurs action. From this reading, theory alone is insufficient. Rather, it is an integral component of tri-partite activity that includes empirical application and actionable findings (Yeung doesn't put it quite this way, but action is the natural outcome of normative and causal research).

I find Yeung's approach to theory appealing, partly because it resonates with the type of theory most employed in the quantitative social sciences and, more narrowly, quantitative human geography. I appreciate the overall framing, as well, though: ‘what kind of theory for what kind of human geography’ (Chapter 3) is a pan-disciplinary question that speaks not only to what we know and how we know it, but also to how we pursue social and spatial justice and how we collectively conceive of our discipline. It deliberately makes space for multiple valid, and valuable, ways of doing geography and geographical theory. This framing, which proposes specific answers to the ‘what kind of theory’ question, also explicitly provides openings for ‘varieties of explanation’, which I interpret as an invitation to embrace theoretical complementarity and diversity. What's not to like?

What about who gets to theorise and who theory is for? Here, mid-range theory suggests the answer is: everyone! Practical theory that is informed by socio-spatial context and is empirically fit-for-purpose indicates not only that empirical research should be theoretically driven, but also that empirical researchers, in their own individual geographical and social contexts, are empowered to develop, repurpose, and extend theory – making, caring, and contributing to disciplinary theoretical infrastructure. Crucially, this mission should include all branches of human geography.

One of the most interesting aspects of Theory and Explanation in Geography may be how it, through various structural devices, highlights the ways in which theory is at once collective and also immensely personal. Theory is collective in its aim to understand and comprehend society. It is also collective in its collaborative and iterative development, expansion, and fine-tuning, involving communities in conversation with each other across time and space. This is an exceedingly useful book for those seeking a twenty-first-century perspective on how we have gotten where we are in human geography, both theoretically and as a discipline. In choosing how to organise theoretical perspectives, and the representatives of those perspectives (i.e. who gets cited), and how conversations shift and grow over time, Yeung provides a sort of ontology of collective geographic thought.

Other points of collectivity in Yeung's book emphasise shared concerns that span sub-disciplines of human geography. In many ways, we are more similar than we are different. The importance of causality is one example. In quantitative geography, causality matters a lot, but is often embodied in data and methods; theory is not asked to do the heavy causal lifting. Establishing causal relationships remains the gold standard of quantitative analysis and research. Theory that is alert to socio-spatial context also resonates. Conceptualising and measuring context drives a substantial amount of empirical and methodological research in quantitative human geography. Similarly, Yeung's allusions to ‘philosophy envy’ in critical human geography parallel concerns that arise in quantitative circles with regard to analysis and methods. It is heartening to learn that although sub-disciplinary concerns about impactful research may vary in focus, they are not unique to any single sub-field.

Theory is also deeply personal. As researchers, it is natural that some theoretical approaches (and theories) will resonate more than others, that, in our academic journeys we will encounter some ways of thinking more than others, and that, in our empirical work, some theory will prove more useful than other theory. So an alternative reading of Yeung's book is as memoir: one human geographer's theoretical journey, outlined in opening and closing chapters that knit together the personal and professional, as well as copious chapter notes that document internal rumination and connections across readings, and, of course, middle chapters that re-interrogate the links between Yeung's own empirical research and theory. I like this particular reading. It drives home, once again, not only the diverse approaches to theory in our discipline but also that this diversity is valuable and worthy of preservation.

We have a saying in quantitative human geography, borrowed from statistics, that ‘all models are wrong but some are useful’ (Box, 1979). It is not, as might appear, an excuse for poor, or incorrect, research, but a reminder that models are intended as abstractions of reality—incomplete by definition. Abstractions, and models, aim to reduce reality down to its salient components, depending on the topic at hand. All models are therefore at least a little bit wrong, but – done correctly and with lots of iteration and ‘right to repair’ – they expose the mechanics of relationships, structures, and behaviours. Theory, I am convinced, is much the same. No single theory, geographical or otherwise, has the power to explain everything. Each individual theory, however, has the potential to be useful: explaining something important about the world, bringing geographers into conversation with each other, providing crucial unifying infrastructure, and adding richness to individual experiences of doing geography. In his conclusion, Yeung exhorts us, as human geographers, to propound and export geographical theory with the slogan, ‘By our explanatory mid-range theories you shall know and learn from us!’ (2023: 266). Perhaps in a collective effort to ‘build back better’ disciplinary infrastructure and solidarity, we human geographers can embrace an accompanying motto, ‘all theories are wrong but some are useful’.