 The advocate thus cries “transmission failure” in relation to (1)–(3), on the grounds that (3) is “presupposed.” Yet in this case, the presupposition charge is not as straightforward. For clarity’s sake, let us call (1) and (2) the “*premises” of the deduction, to contrast them with the premises of the reductio. (The latter are stronger in claiming that the former are apriori.) Then, the advocate bases the presupposition charge on the following: An externalist can rationally grant that the *premises are warranted only if she has certain “background assumptions” which already imply (3). The point is sometimes framed in terms of “information dependence:” An externalist who grants warrant to the *premises “rationally requires certain collateral information” that includes (3) (Wright 2000a, p. 149). Consequently, an externalist’s “acceptance of those [background] assumptions cannot be rationally combined with doubt about the truth of [(3)]” (Davies 2003a, p. 43, but contrast Davies 2000, p. 402).