Of course, there is – especially for those of us with post-structuralist philosophical commitments – no easily discernible, singular, uncontested reality. There are no facts beyond dispute or arguments immune from contestation. No group has privileged access to the truth. Reality has to be narrated and narratives are inherently constructed. But some stories have more support than others, and the “concordance of evidence” favours some positions over others. When anyone flies in the face of such evidence it’s time to get angry and insist that we won’t stand for such BS.I have a few comments as I think this raises a whole load of really interesting questions:
While it's true that a nuanced, epistemologically relativist social theory of knowledge does not preclude the kind of hearty, thorough evidentialism that we so desperately need -- no part of scepticism or constructivism necessitates cynicism or nihilism -- I don't see much in the poststructuralist canon (as I understand it) that provides the theoretical resources for such a discussion. The very notion of evidential 'support' is not a positive concept that I've encountered in poststructuralist writing. Indeed, the very notion implies the kind of epistemological commitments that such writings go out of their way to avoid. That isn't to say that poststructuralist writings do not deploy evidence; of course they do, your own work included. But the theory with which this evidence is articulated tends to be stuck in a critical, narrowly relativist register of admitting that its own account is one theory among many and that it is just 'keeping the discussion going' in Rortyean fashion. Consequently, such accounts generally claim no greater epistemic authority than being one legitimate voice within the discussion.
In my view, saying that "some stories have more support than others, and the 'concordance of evidence' favours some positions over others" goes beyond merely 'keeping the conversation going' -- it takes us into the realm of epistemology proper and a step or two outside the comfort zone of any acknowledged 'poststructuralist' theory that I've ever read. This argument does not, of course, invalidate anything but, if it is correct, it imparts a theoretical burden -- it demands that we acknowledge the inadequacy of what we had previously relied upon and endeavour to go beyond it.
Essentially what you seem to be calling for is what Latour (who isn't generally understood to be a 'poststructuralist', although his thought is certainly related) calls 'political epistemology.' All epistemology, for Latour, is political because epistemology isn't just about how or why we believe what we do -- it's not a neutral theory about the basic mechanics of knowledge; rather, it's about what we should believe and how we can make others believe what we think is right (in every sense of the word). The most obvious kind of political epistemology is the 'demarcation criteria' of scientistic philosophers of science -- of what gets to count as science (and thus be valid) and what doesn't (and what is consequently invalid). But it runs far deeper than that.
As I see it, you can't have 'evidentialism' without a discussion of what does and (importantly) does not count as evidence and this requires active endorsement of particular standards -- a political epistemology or 'political metrology,' if you will. It requires the progressive institution of a collective epistemological reality. This reality is inevitably contested -- indeed, scepticism and contestation are its very conditions of possibility -- but it must also be built up, endorsed, promoted, reinforced, rationalised, validated -- not just cut down, scrutinised, picked apart and deconstructed. It must be active -- in that it creates, circulates and promotes new ideas and instruments -- and not just reactive -- in the sense of picking up on existing discourses and subjecting them to scrutiny. And this brings us to perhaps the biggest challenge for poststructuralism: the need to interrogate the purposes and the limitations of 'critique' and 'critical theory' in general -- of the need for something besides and beyond (or in addition to) these practices.
Latour's new book, coming out in English soon, on 'modes of existence' talks about the need to rediscover trust in institutions, such as science. That is basically the issue: evidentialism requires a kind of epistemic institutionalism, a collective epistemological project based not just on scepticism but also on trust, on belief. This institution needn't be 'scientific' but it needs to be definite and exclusive. It needn't dispense with 'anything goes' as such but it needs to recognise that such epistemic anarchism is but an initial step, logically prior to a more formal sorting process that includes and excludes, legitimating some knowledge claims and delegitimating others. It can no longer be enough to just 'keep the conversation going' by adding one more voice to the mix. That plays straight into the hands of the climate denialists and the gun fetishists, etc. who relish, embelish, exaggerate and exploit epistemic division and uncertainty so as to extract political advantages. Unvarnished epistemological relativism -- in the sense of rendering all knowledge claims formally equal -- is incapable of issuing the necessary clarion call for 'evidence' because what evidence is requires a definite idea of what it is not, which implies an exclusionary distinction.
So, perhaps it's time to reconsider those fusty old epistemology-obsessed modernists who undoubtedly gave us the wrong answers but were nevertheless asking the right questions... They were wrong in arguing that epistemological validity -- i.e. 'Truth' -- was singular, universal and transcendent but they were right in understanding the political need for socially validating some knowledge claims over others. They were wrong in making the validation criteria -- 'Reason, Science,' etc. -- abstract and accessible only to the elites but they were right in understanding that such epistemological criteria are politically indispensible.
We live in an age of 'cynical reason,' as Sloterdijk put it; or, in Latour's words, we live in an age where critique has been 'miniaturised' -- that is, perfected, instrumentalised and woven into the fabric of everyday life such that we scarcely even notice it. The tools and techniques that were constructed for the struggle against power have been internalised by the powerful and turned against resistance itself, hitting it square in its very conditions of possibility. For both these guys this political fact indicates the inadequacy of poststructuralist theory, as received. I tend to agree.
I know that David has been over similar ground in his arguments in print with Colin Wight et al. As I recall he argued then that epistemic validation should be found in ethics rather than epistemology, strictly speaking. I'll shut up now since this is already more essay than comment, but I think it suffices to say that I don't think that 'ethics' alone does the job. The concept of political epistemology seems to me to be a more fruitful avenue, precisely because neither half of the phrase is reducible to the other -- it must be both political and epistemology. If 'evidence' is to have meaningful, positive political force within a poststructuralist understanding of the world, something like Latour's 'institutions' (or perhaps Badiou's 'Truths') are called for. I see room for them within poststructuralism in general but it is just that -- room, empty space yet to be filled.