The talk about John Stuart Mill allegedly saying that stupid people are generally conservative led me to track down the correct quote. I think I now have it, from Public and Parliamentary Speeches by John Stuart Mill, November 1850 - November 1868, at 83 (John M. Robson & Bruce L. Kinzer eds.) (speech on May 31, 1866). (The text I quote below is somewhat different than the text I quoted earlier, which I copied from Michael St. John Packe, The Life of John Stuart Mill 454 (1954); but the differences are immaterial -- I assume the two versions come from different transcriptions of the same speech.) Contrary to some Internet accounts, and to my original impression, the quote is from a parliamentary speech that partly responds to comments by Sir John Pakington, not a letter to Sir John Pakington. Contrary to some uses, but consistent with my earlier view, Mill is explicitly talking about the Conservative party of the time, not about conservatives generally. Also, for whatever it's worth, he gets some digs in at Liberals, too:I desire to make a brief explanation in reference to a passage which the right honourable Gentleman has quoted from a portion of my writings, and which has some appearance of being less polite than I should wish always to be in speaking of a great party. What I stated was, that the Conservative party was, by the law of its constitution, necessarily the stupidest party. (Laughter.) Now, I do not retract this assertion; but I did not mean that Conservatives are generally stupid; I meant, that stupid people are generally Conservative. (Laughter and cheers.) I believe that to be so obvious and undeniable a fact that I hardly think any honourable Gentleman will question it. Now, if any party, in addition to whatever share it may possess of the ability of the community, has nearly the whole of its stupidity, that party, I apprehend, must by the law of its constitution be the stupidest party. And I do not see why honourable Gentlemen should feel that position at all offensive to them; for it ensures their being always an extremely powerful party. (Hear, hear.) I know I am liable to a retort, an obvious one enough, and as I do not intend any honourable Gentleman to have the credit of making it, I make it myself. It may be said that if stupidity has a tendency to Conservatism, sciolism and half-knowledge have a tendency to Liberalism. Well, Sir, something might be said for that -- but it is not at all so clear as the other. There is an uncertainty about half-informed people. You cannot count upon them. You cannot tell what their way of thinking may be. It varies from day to day, perhaps with the last book they have read, and therefore they are as likely to prove Conservatives as Liberals, and as likely to be Liberals as Conservatives. They are a less numerous class, and also an uncertain class. But there is a dense solid force in sheer stupidity -- such, that a few able men, with that force pressing behind them, are assured of victory in many a struggle; and many a victory the Conservative party have owed to that force. (Laughter.)
"sciolism," I'm happy to inform you, is "A pretentious attitude of scholarship; superficial knowledgeability."