Charles Darwin

"About thirty years ago there was much talk that geologists ought only to observe and not theorize; and I well remember someone 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!" – Charles Darwin, in reaction to a critic who said that the Origin of Species was too theoretical, and that Darwin should have just "'put his facts before us and let them rest" (1861)