As we saw in Chapter 1, we are always already involved with a world. For anything to "show up' for us in experience it must bear upon our lived concerns in some way; in a very general sense, it must matter to us. Heidegger expresses the point by saying that involvement (Befindlichkeit) is a basic existential structure, which is to say that we are always attuned to the world in such a way that things disclose themselves as mattering to us (BT: 176). This involvement, moreover, is always accompanied by a particular affective tone: in Heidegger's terms, whatever shows up for us in experience does so in the light of some mood (Stimmung) (BT: 173). So, for instance, to be in an elated mood is to inhabit a world that is fizzing with possibilities. To be depressed is, among other things, to find oneself in a world without hope. Indeed Heidegger suggests that even a relatively detached contemplation of objects present-at-hand is not so detached that it is without its characteristic mood, a "tranquil tarrying alongside' (BT: 177).