According to Derrida, the text "is a differential network, a fabric of traces referring endlessly to something other than itself, to other differential traces. Thus, the text overruns all the limits assigned to it so far" (Derrida 1979: 84). Traditional linear texts have created in the reader an expectation of structural stability as an inherent feature of the physical object text. This assumption is mirrored in spatial metaphors of textuality which create an imaginary textual space of its own.
Spatial metaphors of textuality produce a textual space which guides the reader's orientation in the process of reading. Following Lakoff and Johnson (1980: 3), metaphor is a basic cognitive principle of organization, both of language and of thinking: "metaphor is pervasive in everyday life, not just in language, but in thought and action. Our ordinary conceptual system, in terms of which we both think and act, is fundamentally metaphorical in nature." Metaphor is not just a figure of speech and a linguistic phenomenon, but includes a cognitive dimension. The investigation of metaphor under this conceptual aspect leads to metaphorical systems which show that metaphor is not an arbitrary and singular phenomenon, but a means to express our experience and action. Cognitive experience, cultural and social conventions, provide the framework for the development of cognitive concepts. The importance of space is mirrored in the broad area of spatial metaphors we use, the metaphorical subsystem "space", which Lakoff and Johnson call "orientational metaphors". This metaphoric subsystem has its origin in our everyday experience in space, e.g., our upright posture or movement and orientation in space. Conceptual abstraction from our perception governs the construction of spatial concepts which are applied as metaphorical extensions to other fields of experience.