Abstract All extant “theories” of literature are instances of conceptions of literature; that is, of systems of norms giving rough indications as to the properties literary texts should posses. Conceptions of literature play an important role in the way members of literary institutions speak about literary texts. This paper concentrates on the question whether conceptions of literature also exert a profound influence upon the perception of literary texts. On the basis of a concrete example, Greimas's remarks on isotopy, it is argued that the notion of “isotopy” does not belong to a semantic theory, but to a conception of literature. An experiment is then reported which tests the hypothesis that the considerations underlying the notion “isotopy” might be interpreted as stating a reading program; that is, rules of conduct readers follow in perceiving literary texts. The results of the experiment, however, lead to the rejection of this hypothesis. This provides evidence for the thesis that the notion of “isotopy” reflects a number of institutionalized ideological beliefs about the nature of literary texts and of the way readers process texts.