To find a series of books that join up the dots in whole swathes of one’s previous education is a wonderful experience.  That’s my experience of the writings of philosopher Marinus Dirk Stafleu, which I first discovered a year ago.  His multi-volume project Philosophy of Dynamic Development flows from his career as a Christian studying physics and philosophy: from a PhD in quantum mechanics to teacher-training in Utrecht, in his native Netherlands.

Marinus Dirk Stafleu

In this post I’m reviewing Stafleu’s Theories at Work: On the Structure and Functioning of Theories in Science, in Particular During the Copernican Revolution.  What this title may lack in snappiness is compensated, for me, by its close fit with questions provoked by my undergraduate courses in history and philosophy of science.  Those courses began with the ‘Scientific Revolution’ – the contributions of Galileo, Kepler, Copernicus et al. to the observational and mathematical turn in natural philosophy that laid the foundations for what we now know as physics – and they raised deep questions about the proper way for empirical observations to be combined with rational speculation about how the world works.  Keenly aware of controversies and problems at the interface of science and theology, I was searching for wisdom about a reliable Christian approach to philosophy of science.  I can only wonder how much richer my engagement with those stimulating courses might have been if I’d discovered Stafleu’s writings then.

Theories at Work demonstrates the fruitfulness of categories of Reformational philosophy for illuminating the history of physics, from 16th Century natural philosophy to the enthronement of Newton’s experimental philosophy in the 18th Century.  It was published in 1987; although now out of print (the odd copy still available from online retailers), it’s been incorporated into Stafleu’s online e-book Theory and Experiment: Philosophy of science in a historical context (2016).  The latter extends the historical scope up to the time of James Clerk Maxwell, while a further work, Nature and Freedom (2019), leads up to 20th-century issues in physical and biological sciences.  I hope scientist readers of this blog will join me in adding these to their to-read lists.  But why are they so exciting?

Quite simply, the ideas set forth do what good theories do: they unify diverse phenomena in a parsimonious way.  In historical studies theoretical unification is, I believe, difficult, rare and indeed generally shunned for various reasons.  In philosophy of science unification remains attractive: Karl Popper‘s theory of conjectures and refutations, for example, remains influential alongside newer schemes.  In Theories at Work, Stafleu takes the sequence of modal aspects identified by Dooyeweerd and Vollenhoven as a set of lenses through which to build up a rich description of scientific theory development, which he tests against historical narratives.  He offers a remarkable functional anatomy of scientific theory-building: theoretical concepts are unitary building blocks answering to the numerical aspect; basic law-statements make timeless connections between concepts (a spatial analogy); law-based predictions suggest a kinetic analogy; a theory’s causal explanations give a physical analogy; problem generation a biotic analogy, and so on.  Some readers may find these analogies contrived, yet the way Stafleu illustrates them with detailed historical and anecdotal insights into the work of Galileo, Copernicus et al. adds to their credibility.  Moreover, as shortcomings are pointed out in the models of Popper, Lakatos, Kuhn, Feyerabend and others, we begin to appreciate the originality, nuance and balance of Stafleu’s Reformational model (he moves beyond Dooyeweerd, too). 

The centrepiece of the book is Stafleu’s theory of the opening process, outlined in Chapter 6.  This uses the modal aspects as more than analogies: their sequence provides an order for various modes of scientific advance: ‘upward’ abstraction uncovering modal laws, ‘downward’ specification towards accurate predictions, ‘backward’ moves to mathematisation and ‘forward’ moves to instrumentation, as well as moves ‘left’ and ‘right’ by deduction and induction respectively.  The theory is presented all too briefly, but the careful reader is left with a sense of vast potential for further study, and perhaps even ideas for his or her own research.  Repeatedly I was awakened to limits in my own conceptions of scientific research, and saw new ways of synthesizing the contents of my undergraduate courses.

This book largely conceals its Christian foundations, beyond a few comments that betray the author’s faith.  Part of its appeal for me is seeing how such an original and compelling treatise can arise from foundations that are so profoundly Christian.  But I also believe that the intricate multi-aspectual framework of laws, subjects, relations, individual entities and classes offered to us in Theory and Experiment, which proves so fruitful, constitutes a philosophical realism that is implicitly theistic.  Arguably, it isn’t just theistic: it tessellates with a worldview in which the Lawgiver is also a Subject who seeks a relationship with individual people.  For philosophically-minded scientists, I can’t recommend the book highly enough!


Theories at Work: On the Structure and Functioning of Theories in Science, in Particular During the Copernican Revolution was published by University Press of America in 1987.

Jan 2024: Stafleu’s website is now archived at

Richard Gunton
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Richard Gunton

Richard is the Director of Faith-in-Scholarship at Thinking Faith Network. He also teaches statistics at the University of Winchester. His current passions include Reformational philosophy, history of sciences, ordination (the statistical sort), and wildlife gardening. He worships, and occasionally preaches, at St Mary's Church in Portchester. [Views expressed here are his own.]