Now for the key step. But if this is correct, there can of course be no fact about which function I meant, and if there can be no fact about which particular function I meant in the past , there can be none in the present either. The locus classicus for sceptical solutions is of course Hume's Enquiry . His solution is a sceptical solution to his sceptical problem because it accepts the legitimacy or the upshot of the sceptical doubts concerning reason or the understanding. A straight solution to this problem would consist of showing that Hume's sceptical doubts are faulty and that in fact reason or the understanding is the source of our assurance or our causal conclusions.
Hume proposes however, that custom or habit is the source of such assurance and conclusions.
As such, Hume has accounted for our assurance and our conclusions without having to go back on any of his earlier sceptical doubts about reason or the understanding. As such, he has provided a sceptical solution to the sceptical doubts. See K, p. 66. It requires only that the sceptical solution not go back on, not contravene, anything claimed in the sceptical doubts. Now, what of KW's sceptical solution.