Science, 19th century philosophy of

In the nineteenth century, science was organized, it tested and confirmed positive knowledge of the natural world and achieved remarkable theoretical development and hitherto unimagined practical application. Science drove industry and free enterprise, and became a powerful catalyst in the battle between defenders of knowledge as power and advocates of knowledge as love.

Fruitful scientific theories and observations were plentiful. Darwin, Wallace and Spencer caused a revolution in biology. Faraday, Maxwell and Hertz contributed seminal ideas in electromagnetic theory. Hermann von Helmholtz studied the physiology of tones and discovered a principle of the conservation of force. Lyell’s efforts established geology as a science. Ernst Mach argued for the elimination of absolute space in favour of a space and time consisting of observable relations between things, thus providing incentive for Einstein’s theory of relativity. Sir John Herschel added many observed double stars to the growing catalogue of celestial bodies.

These and other observational, theoretical and applied achievements in nineteenth-century science were replete with philosophical consequences. Until the nineteenth century natural philosophy and science coexisted as a single discipline. Now science and traditional philosophy drew apart. Some held that henceforth science would deal with the world revealed in experience, and philosophy with the world existing (if any does) beyond what we experience. Others (including prominent scientists) were unwilling to yield to philosophy licence to speculate beyond the limits of what could be ascertained by means of observation and experimentation: even if science and philosophy were no longer one unified intellectual enterprise, philosophy had a substantial role to play in philosophizing about science.

To satisfy changing expectations, a new intellectual discipline was created in the nineteenth century: the philosophy of science. Unlike previous philosophy, whose subject matter was everything that is (or is not), the philosophy of science had a distinct and determinate subject matter: theoretical texts and experimental and observational reports of scientists (the word ‘scientist’ having been invented by William Whewell).

Theoretical scientific systems and their logical structure were one focus of attention. Science was also said to discover laws. Were such laws timeless and exceptionless truths about nature, or simply convenient, economical ways of cataloguing information? These laws were discovered (or invented) generalizations that provided tested information about nature. This discovery and confirmation relied upon the method of induction – thought by most nineteenth-century philosophers of science to have a logic – to involve decisions concerning the validity or invalidity of inferences based on knowledge from experience. Was this alleged logic trustworthy? These questions exemplify the complex problems concerning the epistemic reliability of scientific explanation.