 Let’s turn now to Austin’s views specifically about perception  ((5) and (6) above).  Once we have detailed the facts on which a perception-based judgment of ours relies, a more general challenge arises concerning our access to those facts. In order to exploit the bird’s head shape as the basis for our judgment that it is a goldfinch, it is arguable that we must be able to see (or perhaps feel) the bird and its shape. On some views of perception, however, birds and their shapes are not amongst the things that one can perceive. Austin’s main aim in Sense &amp; Sensibilia is to undermine considerations that have been offered in favour of the general doctrine that, as he puts it,