The question of legality or illegality reduces itself then for the Communist Party to a mere question of tactics, even to a question to be resolved on the spur of the moment, one for which it is scarcely possible to lay down general rules as decisions have to be taken on the basis of immediate expediencies. In this wholly unprincipled solution lies the only possible practical and principled rejection of the bourgeois legal system. Such tactics are essential for Communists and not just on grounds of expediency. They are needed not just because it is only in this way that their tactics will acquire a genuine flexibility and adaptability to the exigencies of the particular moment; nor because the alternate or even the simultaneous use of legal and illegal methods is necessary if the bourgeoisie is to be fought effectively.
Such tactics are necessary in order to complete the revolutionary self-education of the proletariat. For the proletariat can only be liberated from its dependence upon the life-forms created by capitalism when it has learnt to act without these life-forms inwardly influencing its actions.
I think Marxist legal theorists need to re-read History and Class Consciousness (see Phil for a recent summary).