Natural science is a branch of knowledge by general consent not primarily based on the a priori. It […] observes and endeavours by observation to follow and trace the 'how' of what happens in Nature. It proceeds further to generalize about this 'how'. It tries to decipher something of it in the past and to forecast something of it in the future. Above all it expends its utmost pains on attempting to describe the 'how' fully and accurately by first-hand observation at this present.
— CHARLES SCOTT SHERRINGTON