lawfulness is the carrot that keeps science going

An example of metaphors in writing about science:

"What ground is there to accept the principle of lawfulness: might it not be just the carrot that keeps science going?
… the search for law – the marrow of scientific research…the principle of lawfulness, as usually understood, is far from being hollow and there is no advantage to emptying it….
And no science lover could sensibly reject this protective and programmatic hypothesis, because to kill the principle of lawfulness would be a worse crime than killing the golden egg hen: it is not just a piece of knowledge but a motor of knowledge."

Mario Bunge

Bunge, M. (2017/1998). Philosophy of Science. Volume 1: From problem to theory (Revised ed.). Routledge.