Theories still useful but maybe proved false?

I don't know if these would constitute "proved false," as a good Marxist would say, "Marx's actual plan has never been put into effect-- USSR and China did it wrong."
And a psychoanalyst would probably say, "Freudian theory works great! You should try it!"

But I think probably Marxist theory and Freudian theory aren't really considered all that viable now. But they're still really useful in analysis, I think. For example, this week I happen to be scoring Advanced Placement exams, the literature ones-- just another of my odd little jobs. And the passage the students were analyzing (it's from a DH Lawrence novel) just cries out for a Marxist critique AND/OR a Freudian critique. That is, even if Marx's proletarian paradise isn't on its way anytime soon, his critique of the dangers of privileging capital over labor is, if anything, MORE apropos these days (what with investment bankers getting a billion dollars bonus and producing nothing tangible). And it very much works to help explain the disruption facing Lawrence's characters at the advent of the Industrial Revolution.

And as for Freud, well, the theory of the unconscious certainly does help explain why, as one student pointed out, the dessicated intellectual author-standin character spends such energy asserting "mastery" over the sturdy, studly, sweaty working class characters. "Methinks," the student opined, "when he scorns that blacksmith, he doth protest too much!"

Pure Freud. (Well, Shakespeare first, but that's one place Freud got the evidence for his theory.)

We know that dark forces within us can make us behave irrationally. Freud's reasons about why (primal horde, Oedipus complex, all that) might be a bit outre, but does anyone deny the power of the unconscious?

So maybe a theory in itself, even if flawed, can be a cognitive tool.