I've read a number of his books, and I reflect on them regularly. They stand the test of time. More important than the specific facts and arguments in his book

I've read a number of his books, and I reflect on them regularly. They stand the test of time. More important than the specific facts and arguments in his books is that he checks up on the results of theories and policies. That's not common enough among social scientists and certainly not among politicians. Does "the peace process" produce peace? Do anti-poverty programs raise people out of poverty? Surely some do, and surely some don't. Figuring out which is which is critical to success -- preferably by learning from others' mistakes, but if not, at least learning from your own mistakes. It's too easy to get a sense of moral superiority just by supporting a policy with a noble intent, and then move on before the consequences arrive.