premise: ( 1 ) When an <mask> was placed in the patient 's hand , he had no difficulty determining whether it was warm or cold , sharp or blunt , rough or smooth , flexible , soft , or hard ; and he could tell , simply by the feel of it , whether it was made of wood , iron , cloth , rubber , and so on .
hypothesis: the proper context for <mask> here should be a tangible and visible entity; an entity that can cast a shadow