The correct answer was given: Brain
This question was raised in the recent debate in applied linguistics between widdowson and de beaugrande involved a dispute about the relationship between text and discourse. widdowson sees the two as distinction. my reading of his position is that discourse is text in use but that texts in corpora or presumably other linguistic collections of language are not discourse. texts need to be 'brought to life' to become discourse. the texts which are collected in a corpus have a reflected reality they are only real because of the presupposed reality of the discourses of which they are a trace. this is decontextualised language which is why it is only partially real. page 5 widdowson, h. g. (2000). on the limitations of linguistics applied. applied linguistics, 21(1), 3-25. de beaugrande argues that a text cannot be contextualised only shifted into a different context. a real text cannot be decontextualised, that is, removed from any context; we can only shift it into a different context, which is an ordinary transaction not just in language classrooms, but in most reports or discussions of what somebody has said. (de beaugrande page 114 from de beaugrande, r. (2001). interpreting the discourse of hg widdowson: a corpus-based critical discourse analysis. applied linguistics, 22(1), 104-121.