"Do we call the claim perception, whether it succeeds or no? Or is 'perception' a 'success word'? J. J. Gibson in his important book, The Senses Considered as Perceptual Systems, defends the view that our senses are systems for information-input from the world. ...Gibson ...interpreted his ...theory as a defence of realism. Hintikka ...objects ...that the claim for 'realism' is merely empirical; the 'logic of perception', he argues, does not demand that the actual world contain the realities of which perception informs, or seems to inform us. ...I cannot go into this argument, since it is based on the articulation of a 'possible-world ontology' which I ...find much too contrived to serve as a philosophical approach to so fundamental a feature of our experience as perceiving ...Gibson’s realistic claim ...and Hintikka’s counterclaim need to be taken seriously—with paradoxical results. 'Perception' is sometimes, justifiably, a success-word, sometimes, justifiably, not."