Discovery through aim-oriented adjustment: The case of the Daniell cell

This talk revisits an old question: is there a method of discovery in science? I start with Dewey's pragmatist view of inquiry as a process of escaping a disturbed situation. Discovery in this mode begins with twisting-and-turning, doing whatever it takes to make something work. There is no algorithm for this process, which I call “aim-oriented adjustment,”, but it is usefully directed by the specific aims and by particular aspects of the problem-situation. And after the solution of the problem at hand arrives, begins the work of understanding why the solution was successful; in this second stage of the process, previously unrecognized theo- retical principles are articulated, developed further, and applied to other situations. These ideas will be illustrated with an example taken from the history of electrochemistry, namely the origin of the Daniell cell. This is the most iconic battery featured in textbooks of chemistry today, and a clear embodiment of the idea that a battery is composed of two half-cells. When John Frederic Daniell initially invented this instrument in London in the 1830s, he did not set out to devise a new conceptual scheme for electrochemistry. Rather, his aim was very prac- tical: to make a voltaic cell that would maintain a constant level of action for a long time, by eliminating interfering factors. But the material configuration of the settled instru- ment pointed to the most stable theoretical way of thinking, which was clarified over a rather long period of time afterwards. Metaphorically speaking: nature guided Daniell’s hands, and thereby also showed him how to clear his head.

Professor Hasok Chang is the Hans Rausing Professor of History and Philosophy of Sci- ence at the University of Cambridge. He received his degrees from Caltech and Stanford, and has taught at University College London. He is the author of Is Water H2O? Evidence, Realism and Pluralism (2012), Inventing Temperature: Measurement and Scientific Pro- gress (2004), and Realism for Realistic People: A New Pragmatist Philosophy of Science (2022). He is a co-founder of the Society for Philosophy of Science in Practice (SPSP), and the Committee for Integrated History and Philosophy of Science.