AbstractThe paper argues for a semiotic – in fact, a grammatical – origin to a profound dimension of the human psyche: William James (1890,1920[1892]) observed how there were far reaching effects from what he characterised as the “duplex self”. This ME/I relation requires cohesion, or co-ordination, much as first suggested by Hughlings Jackson and Théodule Ribot in the mid nineteenth century. The analysis of grammatical equations (identifying clauses) by the functional linguist M. A. K. Halliday can be called upon to show how many important relationships are enfolded in the apparently simple syntax of BE, and of some other cognate verbs. Through detailed exemplification, the paper shows how a double narrative of the “self” is an inevitable consequence of the first person taking on different combinations of grammatical address. This semiotic aspect of the psyche is also discussed in relation to bilaterian or “doubles” in a number of human sciences.