 This enables us to answer the question as it concerns the second objection. It is clear that an argument which has as its focus the question of ostensive definition is not committed to ruling out in advance all hypothetical cases of ‘Robinson Crusoes’. For there is no a priori barrier to imagining a form of life complex enough for us to be assured that a determinate ostensive definition had been accomplished by such a being. Such a Crusoe, unlike a private linguist, lives in a world independent of his impressions of it, and thus there could be definite occurrences in it which he could remember or forget; and some of those occurrences could be correlations of signs with objects. It is easy to describe such hypothetical cases (a clear example appears in pages 486–8 of Canfield [1996]), and difficult to give a plausible denial that in some sense they are possible. There are, however, further complications here, described briefly in section 4 below.