Science is not, therefore, an area of study or even several such areas. You can do science in any area to which scientific methods can be applied including human behaviour and social dynamics. It’s true that studies of people present various distinctive difficulties – but so do astronomy and particle physics.
When thinking about methods in the natural sciences it’s easy to suppose that science requires controlled experiments but this is incorrect. Controlled experiments are impractical in studies of stellar, geological and biological evolution. In medicine some controlled experiments are unethical – that’s why we have ethics committees.
In his wonderful book Guns, Germs and Steel Jared Diamond showed how comparisons between societies and ecologies could be used to illuminate human history and prehistory. In this he applied scientific methods to history – he took a similar approach even more explicitly in Collapse.
Now Diamond has tackled the methodology question head-on. His new book, Natural experiments of history, was written with political scientist James Robinson, and looks at eight ‘natural experiments’, that is sets of historical episodes from which general conclusions can be drawn. In four, similar societies experienced different impacts, eg conquest, whilst in the others different societies experienced similar impacts. The book then compares the consequences in the various cases.
The specific results are interesting, of course, but the real importance of Diamond’s work is to show how scientific method can be applied to the unpromising material of human history.
Truly, science is method, not subject matter.