Expression as Genitive or Generic

Various forms of expressive behaviour are best seen as solutions to the problem of how to make our psychological states and processes known to others. In some cases, natural selection appears to have solved this problem by making our psychological states perceptible to conspecifics. In others we indicate those states in ways that, while not enabling perception thereof, still put appropriately situated others in a position to discern what state of mind we are in. True to their origins in the Latin concept exprimere (meaning to press out), many of the most significant modern practices of expression require those engaging in them to put something of themselves on the table: at least to express one's state of mind, one must be in that state, be it remorse, concern, resentment or certainty about the future. In this way, expression differs from the blander but more labile notion of representation.

Let us set aside semantic expression, such as occurs when an indicative sentence expresses a proposition or a predicate expresses a concept. Within the remainder of the phenomenon of expression, we may differentiate between self-expression and expressiveness. An account of self-expression explains what it is to express one's own psychological state. By contrast, an account of expressiveness tells us what it is for an agent to engage in expressive behaviour even when she is not expressing her own state of mind or feeling; such an account also tells us how an inanimate object may have an affective dimension such as exuberance or melancholy. (We describe some paintings as exuberant and even speak of wind as melancholy.) Non-semantic expression encompasses both self-expression and expressiveness.

Green's Self-Expression (2007) does not offer a general account of non-semantic expression, but rather offers only accounts of self-expression and of certain forms of expressiveness. Yet the work has the resources to provide an account of non-semantic expression per se. (I restrict the theory to non-semantic cases because it would take us too far afield to offer an account of what it is for words, phrases and sentences to express propositions and other kinds of content.) Accordingly, a general account of non-semantic expression is as follows: A expresses psychological state B just in case A either expresses her B (expresses a psychological state that is her own), or A engages in behaviour or possesses features that are expressive of B.