The sociology of ageing has often turned to general sociology in search of useful theoretical approaches, but there has been little cognitive influx back into general theory. By this one-sided relation, the sociology of ageing has typically constituted itself as an applied field. It can be argued, however, that the problems of an ageing society bring forth not only a new topical area but also a challenge for some of the foundations of sociological theory, which were largely laid before these problems became visible. The paper deals with some of the systematic issues that arise in this respect. It takes as its point of departure that modern society has been theoretically conceived as a ‘work society’. If social life is structured around work and its organisation, how can we theoretically cope with a situation in which a large (and still growing) part of the population has left the domain of formally organised work? This question is discussed on three levels: (I) the structure of social inequality (e.g. welfare classes instead of production-based classes); (2) cultural meaning structures (e.g. leisure instead of productivity and achievement); and (3) socialisation (e.g. biographical anticipation and reminiscence instead of a ‘situational’ orientation).