Nancy Cartwright, a philosopher of science whose work probes the limits of scientific laws, says the public distrusts science in part because scientific systems often fail to connect with the realities people live every day. Cartwright, 81, who received the 2025 BBVA Foundation Frontiers of Knowledge Award in the Humanities, has spent decades studying how theory performs when it is applied in hospitals, economics and public policy.
From abstract law to concrete case
Cartwright’s central claim is straightforward: the mathematical or theoretical laws scientists devise do not automatically translate into predictable outcomes when they are applied to the messy conditions of everyday life. She has repeatedly emphasised the importance of testing principles against concrete cases rather than assuming that elegant equations suffice.
Her experience, rooted in philosophical analysis of science in practice, leads her to champion interdisciplinarity. When a discipline operates in isolation it can refine its own methods, she says, but that alone rarely produces the breadth of knowledge needed to act effectively in the real world.
“The idea that only equations matter, or that a single discipline can explain everything, strikes me as odd.”
To illustrate, Cartwright points to the construction of a high-precision physics experiment — such as an instrument designed to test relativity. Producing a working device depends not only on theoretical physics but also on expertise in materials, engineering, optics and the properties of specific substances such as fused quartz. Those practical specialisms are essential for turning equations into functioning apparatus.
| Discipline | Role in an experiment |
|---|---|
| Materials science | Choose and prepare suitable substances |
| Engineering | Design and assemble mechanisms |
| Optics | Shape and control light for measurements |
| Special materials (e.g. fused quartz) | Provide specific physical properties required |
Implications for public policy and trust
Cartwright’s critique has direct implications for how governments, health systems and policy-makers present and apply scientific guidance. If advice is delivered as abstract law or prediction without clear attention to local conditions and implementation needs, citizens may perceive science as distant or irrelevant. That distance can feed distrust.
Her work encourages researchers and policy teams to ask practical questions: what else must we know to make this work here? Which local skills, materials or institutional arrangements are needed? The answers often reach beyond a single scientific discipline.
- Testing in context: Cartwright stresses the need to evaluate theories where they will be used, not only under idealised laboratory conditions.
- Interdisciplinary collaboration: Real-world problems usually require combined expertise from multiple fields.
- Attention to implementation: Technical solutions must be matched with realistic plans for materials, manufacturing and maintenance.
Her position also cautions against overconfidence in deterministic models — the idea that, given the laws, outcomes can be predicted exactly. Cartwright argues that the world’s complexity often frustrates such neat predictability, and that admitting this fragility is part of rebuilding public trust.
For science communicators and policy-makers in South Africa, the lesson is practical: communicating uncertainty, acknowledging limits, and showing how scientific advice has been adapted to local conditions may help close the gap between experts and the public. Cartwright’s work does not reject science; rather, it demands that science be connected more visibly to the practical skills and contextual knowledge that make it work.
Her career — spanning philosophy, case studies in medicine and economics, and reflection on governmental practice — offers a reminder that the credibility of science depends as much on the quality of implementation and the inclusiveness of the process as it does on the accuracy of equations and models.
