Irregularity as a determinant of morphological change

In morphology, as in other branches of scientific endeavour, apparent disorder and irregularity tend to be re-analysed as underlying order. Asymmetries between form and meaning, such as allomorphy, tend accordingly to be factored into basic invariance,2 sames of meaning being interpreted, where possible, as sames of form. Alternatively, as in some of Bybee's (1985) analyses of fusional allomorphy, differences in form may be viewed as diagrammatic of differences in meaning. Allomorphic variants which cannot be made to yield to such re-analyses are commonly relegated to a kind of marginal synchronie ‘junkpile’, and are assumed to be a synchronically ‘inert’ residue of historical (usually phonological) changes. That such an approach to allomorphy can often be illuminating is not in question, but it bespeaks an essentially negative view of morphological irregularity. I wish to propose that there is room for a complementary perspective, in which the ‘irregularity’ inherent in allomorphy can be appreciated not as basically ‘inert’ deviation from a natural isomorphic relationship between meaning and form, but as an active, abstract structural property of morphological systems.