I checked Twitter a minute ago and learned that Ronald Coase has passed away. Coase's contributions were...Coasean. I'm not sure if I can think of a strong enough adjective to describe what he did in just two articles--"The Nature of the Firm" and "The Problem of Social Cost"--to say nothing of the rest of his work.
A few months ago, I was talking to the philosopher David Schmidtz, and he said that as famous as Adam Smith is, he's still underrated. The same can be said for Coase: "The Problem of Social Cost" is one of the most influential articles in law and the social sciences, and yet a few minutes with the "externalities" section of almost any principles book, or a few seconds watching and listening to TV and radio discussions of environmental policy--suggests that it is not influential enough.
Farewell, Professor Coase. The world is a better place because you were here.