The role, in Popper's work, of intersubjective assessment of empirical claims - which, if my suggestions above are accepted - may also be extended to the ethical, also suggests a further line for the development of critical rationalism which would take it into areas that are currently occupied by Habermas and his followers.
For intersubjective consensual assessment (which, of course, is typically something to which we will aspire, rather than actually reach) will only play its appropriate epistemological role if it is reached freely. Someone in the subway cannot claim that I expressed consensual agreement to some claim of his (to the effect that he should have my wallet), when he had a knife pressed into my ribs at the time. And we cannot claim, say, that some proposal has passed the scrutiny of critical discussion with flying colours if, at the time, the women members of the relevant group were prevented from voicing their objections because they had, by custom, at that point to leave the room to make tea and sandwiches.
All this suggests that the epistemology of critical rationalism has within it facilities upon which we can call in the scrutiny of social arrangements, insofar as we are interested in truth and in the validity of ethical claims. This suggestion, if accepted, leads to a further question concerning which kinds of economic and political arrangement are most appropriate, from such a perspective. Into this issue I cannot now enter - other than to suggest that the answer to which I think that we will be led is rather different from that which is usually read out of Habermas's theory of epistemologically-guided social criticism, and is closer to classical liberalism than to any form of socialism. This approach also suggests how we might develop a sociology of knowledge of a non-relativistic character - in the sense that we might explain defects in specific theories in terms of the kind of inter-subjective criticism to which they have not been submitted, by virtue of particular social arrangements.