The Worldly Philosophers
John Maynard Keynes, perhaps the greatest political economist of the 20th century, once said that in the long run, the course of history is determined as much by ideas and intellectuals as by politicians. He did not mean special advisers, or producers of programmes for immediate use and writers of speeches for presidents and prime ministers. Nor did he mean the newspaper and television commentators and pundits whose writings provide the background music to politics. He meant the authors of truly seminal ideas, like his own notion that from time to time capitalism must be saved by state intervention to manage aggregate demand.
Keynes, of course, also reminded us that in the long run we are all dead. When his own influence was greatest--in the 1950's and, above all, the 1960s--he in fact was dead. Others who had inspired (if that is the correct word) the totalitarian menaces of the 20th century had long been dead by the time their ideas came to fruition. Thus, the political effect of intellectuals is rarely immediate. It must bide its time.
This has to do with another characteristic of the great ideas that define historical periods, namely the fact that they come from the margin of prevailing orthodoxies. When first produced and published, these ideas seem almost irrelevant, and at any rate out of tune with the spirit of the times.