Here is today’s attempt.
The phrase ‘diverse logics’ (from my Bulgarian sponsors) suggests that, in psychiatry, we find different ways of going on, different forms of mindedness from our own. This sounds like the ‘lost tribe romantic’ view of mental illness (in Andy Hamilton’s phrase). But is it plausible? Can we make intellectual space for such a possibility?
A clear view of the matter seems to me to be driven by the interaction of two opposing tendencies, however. On the one hand, there is the view of conventionalist and constructionist interpretations of Wittgenstein. Bloor, for example, invoked Wittgenstein in defence of the idea that, contrary to Mannheim’s reluctance on the matter, a thorough going sociology should not only embrace scientific rationality but also mathematics and logic. To the extent that sociological explanation of one way of going on requires that others were possible, everything is up for grabs. That suggests space for diverse logics.
(An opposing view would be that of Jonathan Lear. He thinks that it is significant that the sketches of alternative ways of going that Wittgenstein offers - those elastic rules and selling of wood by area - are so thin. In fact, they are intended as reductios of the idea that there could be alternatives to our form of mindedness. But I'll ignore him today.)
The opposing tendency (the one I am interested in today), however, is expressed in Davidson’s ‘On the very idea of a conceptual scheme’. Reluctant to drive the conclusion by a swift sympathy with verificationism (that only what we can recognise to be a linguistically articulated worldview is one), Davidson argues that we can make no sense of the key metaphor for such other ways of going on: that they are different ways of organising or fitting either the world or experience. A worldview is what is revealed through the process of the radical interpretation of agents’ speech and action already located in their natural environments, a process in which the interpreter’s own standards of truth and rationality play a constitutive role.
A quicker route to the same endpoint can be found in McDowell’s Sellarsian point that splitting a worldview into a (collectively) subjectively imposed conceptual structure and an extra-conceptual brute contribution from the world results in either a frictionless spinning in the void or a constraint which is at best an exculpation rather than a justification. The solution is to deny that the conceptual and worldly are notionally separable contributions. Experience, and indeed the world, is always already conceptually structured (because ‘world’ is a world of facts, of true contents of thoughts, not of things).
But does this not threaten to be too strong? If the world is not an extra conceptual thing in itself but revealed in an interpretation, an interpretation constrained by the principle of charity, does this not threaten to rule out not merely genuinely diverse logics but also everyday inconsistency?
Bortolotti presents this worry as a dilemma for Davidsonians. Either rationality is directly manifested in speakers’ performance, in which case inconsistency would, impossibly, be ruled out. Or, if it is merely an underlying commitment of speakers, then it cannot detectably constrain their manifest performance. But that was the only argument for introducing it through charity.
I don’t think that this objection is fundamentally different from an objection to the holism of belief and meaning. Since I am prepared to buy the idea that that holism isn’t an epistemic barrier (any more than the epistemic holism of the Duhemn Quine thesis is an impossible barrier to knowledge), the idea that commitments to rationality are sometimes only indirectly visible in correcting behaviour (cf Wittgenstein’s parade ground soldier) seems innocent enough. Given that agents aim at or for truths (truths if not truth seem a norm for inquiry), the aim should often enough be manifested.
What then of ‘diverse logics’? Davidson’s argument suggests that constructionist Wittgensteinians were wrong to disregard Wittgenstein’s aim to leave everything as it is. The failure of supernatural foundations for the conceptual order does not imply it is a mere convention (including also, eg., the logical consequences of the conventions). But adopting a broadly Davidsonian approach need not rule out instances of failures of logic. That, however, seems to undermine rather than support the idea of diverse logics.
Bortolotti, L. (2005) ‘Delusions and the Background of Rationality’ Mind and Language 20: 189-208.
Davidson, D. (1984) ‘On the very idea of a conceptual scheme’ in Inquiries into Truth and Interpretation, Oxford: Oxford University Press
Lear, J. (1982) ‘Leaving the world alone’ Journal of Philosophy
Lear, J. (1984) ‘The disappearing “we”’ Proceedings of the Aristotelian Society supplementary volume 58
Lear, J. (1986) ‘Transcendental anthropology’ in Pettit, P. and McDowell, J. (eds) (1986) Subject Thought and Context, Oxford: Clarendon Press
McDowell, J. (1994) Mind and World, Cambridge, Mass.: Harvard University Press.