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Russell's Transcendental Argument in: An Essay on the Foundations of Geometry

It is also worth noting at this juncture the argument Moore gives in NJ for the realist commitment he opposes to what he takes to be Russell's point here. It is remarkably weak. Writing of 'the nature of a proposition or judgment' Moore says, 'A proposition is composed not of words, nor yet of thoughts, but of concepts. Concepts are possible objects of thought; but that is no definition of them. It merely states that they may come into relation with a thinker; and in order that they may do anything, they must already be something. It is indifferent to their nature whether anybody thinks them or not' (NJ 179). 'Concepts form a genus per se, irreducible to anything else' (NJ 178-9). This Platonism about concepts itself seems to be enthymematically premissed, among other things, on the view that relations of acts of judging to their contents are external. But nothing is offered in support of that claim, and no other reason–of the better kinds needed–is offered for hypostasising concepts and judgments. Since Moore goes on to assert that the world is made of concepts, thus realistically conceived, some such argument is surely called for. (In Frege one at least has a strong motivation for assigning Thoughts to a Platonistically-conceived Third Realm, namely that the publicity constraints on sense require that it have a greater degree of objectivity than mappings across the psychological states of language-users can yield. I argue elsewhere that Frege's requirement, backed as it is in this coherent way, is overstrong.)

Russell's transcendental argument has it, as we saw, that a form of externality is necessary for the possibility of experience, because the givens of experience are complexes, that is, have parts which must be external to each other. Moore's first point is directed at this proposition. He quotes Russell's claim that necessity always involves a ground, and says, 'But this ground must itself either be simply categorical, or else it must itself be necessary and require a further ground'. In the former case we are actually trying to deduce an a priori proposition from one that, as categorical, is merely empirical; in the latter, which Mr Russell seems in the end inclined to accept, we must either allow an infinite regress of necessary propositions, and thus never reach the absolutely a priori, or else we must accept the view that knowledge is circular, and shall in the end return to the proposition from which we started as empirical, as being itself the ground of necessity of the a priori, and therefore itself as much a priori as the latter. Mr Russell seems actually to accept this latter view (pp 57-60)–a view which renders his logical criterion nugatory, since it asserts that 'that which is presupposed in the empirical equally and in the same sense presupposes the empirical.'

Moore is here arguing in effect that, leaving aside a regress of conditions which never terminates in an absolute a priori, however one otherwise tries to state the case the starting point is the nature of experience and the conclusion concerns what is required for it to be thus and so; and therefore 'to show that a "form of externality" is necessary for the possibility of experience, can only mean to show that it is presupposed in our actual experience' (CN 399). And Moore immediately sees that 'this can never prove that no experience would be possible without such a form, unless we assume that our actual experience is necessary, i.e. that no other experience is possible' (ibid).

It no more occurred to Moore to consider whether this ancillary requirement can be met than, evidently, it occurred to Russell, who like most Kantians might have simply accepted that Kant was right to allow the possibility of other forms of experience–for example he allowed that animals might have forms of spatial experience quite different from ours. For this reason Moore read Russell as having to find another way out for the argument, and therefore attributes to him what he calls the 'subterfuge' (ibid) of the presuppositional argument. Moore thus views Russell's point about presuppositions as an ad hoc step taken to avoid a difficulty, not as a characterisation of the argument to the necessity of a form of externality itself. As we saw, in this he is wrong. For it is of the essence of a transcendental argument that, in identifying what is necessarily presupposed to something which is the case, it tells us something else about what is the case as its condition. Instead of being a criticism of Russell's strategy, Moore's anatomisation describes it.

But it does show that the condition identified as necessary for spatial experience is relative unless the ancillary requirement be met that no alternative experience is possible. At first sight this seems to pose too tall an order. But subsequent debate in philosophy has provided an interesting if controversial means of showing that there might indeed be a way to satisfy the requirement. (A polite form of execratory howl usually greet this assertion, chiefly because of now orthodox assumptions about possibility. When possibility is understood as an epistemic notion–as conceivability, in other words–the task is recognisably much more manageable. But the argument I'm about to borrow does not require a demonstration that most philosophers until the time of Kant were right to construe the modalities–all of them–as epistemic notions.) The argument, furnished by Davidson, is his celebrated case for saying that the idea of alternative conceptual schemes is incoherent. It has more texture than I am going to bring out here , but in any case I only need its bones for present purposes. The argument goes as follows.

The idea of 'other ways of having experience' can be generalised into the idea of alternative conceptual schemes–alternative, that is, to our own, for arbitrarily constrained 'us' (it does not matter how restrictive one is about who 'we' are in talk of 'our' conceptual scheme, for the argument goes through whatever one says about this)–and conceptual schemes can be provided with criteria of identity by identifying them with languages or sets of intertranslatable languages. Then, in turn, questions about the possibility of the existence of conceptual schemes other than our own, perhaps existing undetectably from the point of view of our own, can be framed in terms of translatability. In this idiom, the question of whether there can be other or alternative schemes comes down to the question of whether there can be languages that we cannot translate. But since we can have no grounds for treating as a language anything that cannot be translated into our own language–since, in effect, the criterion of languagehood is 'translatability into a familiar idiom'–and since intertranslatability defines membership of the same scheme, the conception of distinct schemes–in particular, of mutually inaccessible schemes–is seen to be incoherent. But to say that there can be no such thing as an alternative scheme is, transposing back into the idiom of ways of experiencing, to say that ours can be–still taking our modalities seriously–the only such way. The argument is a strongly anti-relativist one; which is appropriate, because Moore's rebuttal of Russell's project takes precisely the form of a sceptical counter-claim to the effect that forms of experience are relative. As is usual, no argument is offered for the claim: its sole ground seems to be the now orthodox view of possibility mentioned.

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