I consider their contribution to the body of human knowledge or humanity to be of quite dubious merit. Very smart and successful businessman for sure, very good at enriching themselves, but that's about it. At best they can be compared to Rockefeller, Edison, that too at best.

On the other hand one can argue that a lot of our material welfare (as a product of science and engineering) is a direct consequence of Newton's accomplishments. Of course he did not start the fire all by himself.