>Quantum mechanics was condemned also on the grounds of
>it being idealist & subjectivist, and because quantum indeterminism
>was seen as incompatible with the postulates of materialism (which
>was seen as being committed to a fullblooded determinism).
Quite so -- this delusion illustrates the continuity between Bernstein's revisionism and that of the Stalinists. It's a strange quirk of intellectual history that Bernstein is remembered for (supposedly) providing a critique of Marx and Engels' (alleged) determinism, when in point of fact it is Bernstein who is the dogmatic determinist.
Both the D of N and the Anti-D contain absolutely clear, indeed scathing, attacks on "mechanical materialism" and the associated determinism. Moreover Engels specifically describes that sort of determinism as a doctrine especially suited to the viewpoint of the rising bourgeoisie (in particular reference to the Calvinists, as it happens).
Nonetheless, Engels doesn't in the end do a very good job of articulating a dialectical materialist position on determinism and free will (though he has a very clear and pithy comment on how it is the exercise of every one's free will, in an atomised society, that creates the appearance of iron constraints).
Marx, it might be noted, makes several comments -- in connection with such issues as the formation of the general rate of profit, the relation between prices and values, etc. -- which to my mind show a clear (but purely intuitive) probabilistic point of view.
Unfortunately, it seems that neither of them consistently followed 19th century statistical debates. In particular, there was a spirited controversy over whether the discovery of social regularities (Quetelet's "homme moyen") implied determinism.
Interestingly (but unsurprisingly to anyone aware of Engels' remarks about the Calvinists) the proponents of what was called "statistical fatalism" were adherents of Manchester-style liberalism. The stronghold of free-will was the Prussian statistical bureau and the German professor-socialists.
On a slightly different note, is it really true, as Jim suggests, that
>much of the Soviet physicists' defense of relativity
>consisted of their pointing out the degree to which Engels
>had in fact anticipated the insights of Mach and of Einstein.
Given the pasting which Lenin gave Mach in "Materialism and Empirio-Criticism" I should have thought this line was best avoided in the Stalin era.
Julian