Science is an exquisite blend of data and theory

Writing to a friend on September 18, 1861, Charles Darwin reflected on how far the science of geology had come since he first took it up seriously during his five year voyage on the HMS Beagle:

About thirty years ago there was much talk that geologists ought only to observe and not theorise; and I well remember some one saying that at this rate a man might as well go into a gravel-pit and count the pebbles and describe the colours. How odd it is that anyone should not see that all observation must be for or against some view if it is to be of any service!

For my money, this is one of the deepest single statements ever made on the nature of science itself, particularly in the understated denouement. (continue reading…)