Alan Jacobs

In English we speak about science in the singular, but both French and German wisely retain the plural. The enterprises that we lump together are remarkably various in their methods, and also in the extent of their successes. The achievements of molecular engineering or of measurements derived from quantum theory do not hold across all of biology, or chemistry, or even physics. Geophysicists struggle to arrive at precise predictions of the risks of earthquakes in particular localities and regions. The difficulties of intervention and prediction are even more vivid in the case of contemporary climate science: although it should be uncontroversial that the Earth’s mean temperature is increasing, and that the warming trend is caused by human activities, and that a lower bound for the rise in temperature by 2200 (even if immediate action is taken) is two degrees Celsius, and that the frequency of extreme weather events will continue to rise, climatology can still issue no accurate predictions about the full range of effects on the various regions of the world. Numerous factors influence the interaction of the modifications of climate with patterns of wind and weather, and this complicates enormously the prediction of which regions will suffer drought, which agricultural sites will be disrupted, what new patterns of disease transmission will emerge, and a lot of other potential consequences about which we might want advance knowledge. (The most successful sciences are those lucky enough to study systems that are relatively simple and orderly. James Clerk Maxwell rightly commented that Galileo would not have redirected the physics of motion if he had begun with turbulence rather than with free fall in a vacuum.)

The emphasis on generality inspires scientific imperialism, conjuring a vision of a completely unified future science, encapsulated in a “theory of everything.” Organisms are aggregates of cells, cells are dynamic molecular systems, the molecules are composed of atoms, which in their turn decompose into fermions and bosons (or maybe into quarks or even strings). From these facts it is tempting to infer that all phenomena—including human actions and interaction—can “in principle” be understood ultimately in the language of physics, although for the moment we might settle for biology or neuroscience. This is a great temptation. We should resist it. Even if a process is constituted by the movements of a large number of constituent parts, this does not mean that it can be adequately explained by tracing those motions