"In attacking Anderson and Nairn, Thompson did not consider that he was simply correcting erroneous interpretations of history. He saw himself as defending the practice of historical materialism against an empty formalism which characterised too much Marxist analysis. 'Minds which thirst for a sturdy platonism very soon become impatient with actual history', he suggested. A decade later, his defence of 'actual history' against 'platonic Marxism' took the form of a no holds barred attack on the structuralist Marxism of Louis Althusser.

Thompson's critique of Althusser developed points which had been made by other writers.16 What distinguished Thompson's attack, The Poverty of Theory, however, was its fierce polemical tone and its attempt to demonstrate that Althusser's position was saturated with Stalinism. Not surprisingly, Thompson's polemic begins with an assault on the contempt for history that characterises his adversary's project. Thompson quotes the astonishing statement by two British Althusserians that 'Marxism, as a theoretical and political practice, gains nothing from its association with historical writing and historical research. The study of history is not only scientifically but also politically useless.'17 And he proceeds to demonstrate that Althusser's system is nothing less than the wildest form of idealism.

Central to Althusser's position was the idea that Marxist science could be constructed only at the level of philosophy by means of the pure refinement of concepts. Any contamination of theory by history, any attempt to ground concepts in lived experience, he denounced as 'empiricism'. It followed that Marxist science could be developed only at a conceptual level, by refining concepts by means of other concepts. Thompson had no doubt as to the thoroughly idealist nature of this theoretical operation:

...this procedure is wholly self-confirming. It moves wholly within the circle not only of its own problematic but of its own self-perpetuating and self-elaborating procedures... It is a sealed system in which concepts endlessly circulate, recognise and interrogate each other.

Such a position is neither scientific nor materialist. And Thompson did not shrink from giving it a name. Althusser's theoretical enterprise, he wrote:

is a break from disciplined self-knowledge and a leap into the self-generation of 'knowledge' according to its own theoretical procedures: that is, a leap out of knowledge and into theology.18

The tone of Thompson's spirited polemic offended many academic Marxists. Yet Thompson's combination of satire and denunciation with theoretical argument was nothing new in Marxist polemics against idealism--one need only consult the tone adopted by Marx and Engels in a work like The Holy Family to see that The Poverty of Theory has its place in a long and honourable tradition. But Thompson's essay offended in large measure because of the political and social characterisation of Althusserianism it contained.

Thompson notes the origin of Althusser's work: 1956. And he recognises that Althusser's project was defined by an effort to render the Communist Parties immune from the sort of criticism which was emanating from libertarian communist and socialist humanist quarters. The easiest way to do that was to eliminate human beings from the project of 'Marxist' science. To that end, Althusser sought to bury Marx's concepts of alienation and reification and to reconstruct Marxist science as a philosophy of structures. But Thompson, seasoned in the battles of 1956, understood the political character of Althusser's project. 'We can see the emergence of Althusserianism', he wrote, 'as a manifestation of a general police action within ideology, as the attempt to reconstruct Stalinism at the level of theory.'19"

http://pubs.socialistreviewindex.org.uk/isj61/mcnally.htm

Maybe it's because I'm a Londoner - that I moved to Nice.