Scientific understanding

A perspectives piece in Nature on AI and science provides a nice description of scientific “understanding” that I want to share here:

Scientific understanding

Imagine an oracle providing non-trivial predictions that are always true. Although such a hypothetical system would have a significant scientific impact, scientists would not be satisfied. They would want “to be able to grasp how the predictions are generated, and to develop a feeling for the consequences in concrete situations”¹³. Colloquially, we refer to this goal as ‘understanding’, but what does this really mean? To find criteria for scientific understanding, we seek guidance from the philosophy of science… Numerous philosophers [have tried] to formalize what ‘scientific understanding’ actually means. These proposals suggest that ‘understanding’ is connected to the ability to build causal models (for example, Lord Kelvin said “It seems to me that the test of ‘Do we or not understand a particular subject in physics?’ is, ‘Can we make a mechanical model of it?’”¹³), connected to providing visualizations (or Anschaulichkeit, as its strong proponent Erwin Schrödinger called it^26,27) or that understanding corresponds to providing a unification of ideas^28,29.

More recently, Henk de Regt and Dennis Dieks have developed a new theory of scientific understanding, which is both contextual and pragmatic^12,13,24. They found that techniques such as visualization or unification are ‘tools for understanding’, thereby connecting previous ideas in one general framework. Their theory is agnostic to the specific ‘tool’ being used, making it particularly useful for application in a variety of scientific disciplines. de Regt and Dieks extended Werner Heisenberg’s insights³⁰ and, rather than merely introducing theoretical or hypothetical ideas, the main motivation behind their theory is that a “satisfactory conception of scientific understanding should reflect the actual (contemporary and historical) practice of Science”. Simply put, they argue that: “A phenomenon P can be understood if there exists an intelligible theory T of P such that scientists can recognise qualitatively characteristic consequences of T without performing exact calculations”^12,13. de Regt and Dieks defined two interlinked criteria:

• Criterion of understanding phenomena: a phenomenon P can be understood if a theory T of P exists that is intelligible.
• Criterion for the intelligibility of theories: a scientific theory T is intelligible for scientists (in context C) if they can recognise qualitatively characteristic consequences of T without performing exact calculations.

We decided to use this specific theory because it can be used to ‘experimentally’ evaluate whether scientists have ‘understood’ new concepts or ideas, rather than by inspecting their methodology, by simply looking at the scientific outcome and the consequences. This approach also coincides with Angelika Potochnik’s argument that “understanding requires successful mastery, in some sense, of the target of understanding”¹¹.

Scientific discovery versus scientific understanding

Scientific understanding and scientific discovery are both important aims in science. The two are distinct in the sense that scientific discovery is possible without new scientific understanding… Many discoveries in physics occur before (sometimes long before) a theory or explanation, which provides scientific understanding, is uncovered. Examples include the discovery of superconductivity (and its high-temperature version), the discovery of the cosmological microwave background, neutrino oscillations and the discovery of a zoo of particles before the invention of the quark model.

These examples show that scientific discoveries can lead to scientific and technological disruption without directly contributing to scientific understanding^11,24.