My first two posted lectures have provoked so many thoughtful comments that I must stop me work on Lecture Four [Three is ready to post] in order to attempt some sort of response. Here goes, in no particular order.
First, let me just say a heartfelt thank you for the very kind comments. They mean more to me than you might imagine.
Now, to work:
Andrew MacDonald said: "Found the first lecture very interesting. Mannheim's idea that one must go back to the origins in order to understand a thought is interesting (reminiscent of Nietzsche and Foucault). I wonder if we could also say that along with this backwards movement one must also engage in a horizontal movement; relating the thought to the context of significance it inhabits at this particular place and time."
Absolutely. I hope I conveyed that in my extended Marx example. I chose the story about my childhood because it struck me as an example people would not immediately think of. Mannheim's own examples of ideological thinking very often make this "horizontal movement."
Formerly a wage slave said: "Steve Keen made an argument along the same lines in his "Debunking Economics". That is, he argued that there are articles in mainstream economics journals that undermine most of what's taught (at undergraduate levels) as Economics and also that the same refuted doctrines influence policy. Keen suggests those articles are either ignored by Economists, or it is assumed that the details of the math. is someone else's job. In Ha Joon Chang's remarks about Neo-Classical Economics in his "Economics; a User's Guide" he says something along the lines that it's not the overwhelming evidence on the side of the theory which has made Neo-Classical economics dominant."
I think the situation is a bit worse than this. Only ideological blindness can explain the fact that professional economists who do indeed know better [as I argued] nevertheless appeal to arguments they know are inapplicable to justify policy positions that serve the interests they consciously or unconsciously serve. Some of them are just con artists and frauds, but the best of them, I believe, are truly in the grip of an ideology they cannot see for what it is.
As I have several times observed, Freud says somewhere that if there is one subject one cannot discuss in an analysis, sooner or later the entire analysis comes to be about that one subject. For economists like Krugman, Marx is that subject.