 Partly due to the difficulty of specifying precisely the stimulus conditions and manifestations of a disposition and partly due to the doubt over its philosophical relevance, philosophers find it useful to distinguish two sorts of disposition, or alternatively, two ways of referring to dispositions. Conventional dispositions are typically expressed by such simple predicates as ‘fragile’, ‘soluble’, ‘flammable’, and so on, which include no explicit reference to their stimulus conditions and manifestations. Canonical dispositions, on the other hand, are explicit about their stimulus conditions and manifestations, couched in the overtly dispositional locution. Some examples of canonical dispositions are the disposition to break in response to being struck, the disposition to cause death in response to being ingested, and so on. Obviously, the two ways of expressing dispositional properties are related to one another. As noted earlier, (water-)solubility might be identified with the disposition to dissolve in response to being put into water although this kind of identification is not readily available in many other cases of conventional disposition. This distinction between conventional and canonical dispositions allows us to keep questions about the adequacy of different analyses of dispositions sharply distinct from questions about how to identify the stimulus conditions and manifestations of particular dispositions.