David Hume died on this day in 1776. He was, by my reckoning, the greatest philosopher of the empirical school. I chose his Enquiry Concerning Human Understanding as one of my all-time greatest books. I said:

What a joy it is to watch an intelligent mind thinking. Hume asks how we know things, and starts with himself. He muses about the status of sensory inputs. What is it that happens when we think we see something? We suppose the presence of an external world as the source of the inputs to our senses, but what evidence have we other than those senses themselves?

Hume concludes that our knowledge is more tentative than we suppose. His Enquiry is thus an ultimate anti-system book, with a covert sub-text of liberalism. If knowledge is that hesitant, wherein comes the authority to insist upon systems and to impose them?

Adam Smith, remembering him in a letter to William Strachan, delivered a famous epitaph:

Thus died our most excellent, and never to be forgotten friend; concerning whose philosophical opinions men will, no doubt, judge variously...but concerning whose character and conduct there can scarce be a difference of opinion... Upon the whole, I have always considered him, both in his lifetime and since his death, as approaching as nearly to the idea of a perfectly wise and virtuous man, as perhaps the nature of human frailty will permit.