There used to be a story according to which empirical inquiry works by first giving senses to notions, and then scouting around for something for the notions to apply to. It was a sort of sophisticated version of Nanny's advice always to start by defining one's terms. What a strange business philosophy is. Putnam's discussion of representation and perception is, however, less abrupt. I'll concentrate on that.
Common sense observes that typical states of the cognitive mind are representational.
But there is a venerable project, in both philosophy and psychology, of trying to construct a general theory of the mind grounded in this common sense observation. The goal, in short, is to make predictive and explanatory science out of commonsense mentalism. But its avatars in current cognitive science are directly indebted to a philosophical tradition that has been continuous at least since the 17th century. Occasional flirtations with behaviourism not-withstanding, representational theories are the mainstream tradition of Western thinking about the mind. Putnam is not, however, an enthusiast for this mainstream tradition.