  Millikan (1998) espouses a parsimonious conception of conventions that she terms ‘natural conventions,’ and on the assumption that natural conventions are a type of convention, one would expect this strategy to make it easier to defend the view that speech acts are inherently conventional. For Millikan, a natural convention is constituted by patterns that are reproduced by virtue of the weight of  precedent.[11]  A pattern is reproduced just in case it has a form that derives from a previous entity having, in certain respects, the same form, and in such a way that had the previous form been different in those respects, the current form would be different in those respects as well (1998, p.  163). Photocopying is one form of reproduction meeting these criteria; the retinotopic mapping from patterns of stimulation on the retina to patterns of stimulation in the visual cortex is evidently another. Millikan would not treat retinotopic mapping as a type of convention, however, since it would not seem to be perpetuated by virtue of the weight of precedent. The point is difficult to discern, however, since in her discussion of the matter Millikan discusses the conditions under which a pattern is taken to be conventional, rather than for it to be conventional, writing