Piaget and his followers seriously denigrate the role of language in symbolic thought by denying that it plays a process (operative) role in the transformational and combinatorial aspects of thinking. It is shown that both the representational function of words in designating ideas, and the refining function of verbalizing emergent products of thought, are crucial operative aspects of thinking. The very emergence of complex logical operations ("interiorized actions," according to Piaget) would also be inconceivable in the absence of language. Thus preoperational (prelinguistic) thought is qualitatively discontinuous with operational (linguistic) thought.