The formulation of the problem of justice among generations as the problem of finding an ordering of infinite utility streams is examined within the ‘social welfare functional’ approach to social choice. This formulation usually presumes a double reduction not only the classical ‘welfarist’ reduction, according to which ‘utility’ provides all the information required to construct a social evaluation rule, but also the aggregation of the individual utility levels at each generation into a single utility level. We shall argue that this second type of reduction obliterates the relationship between the values judgments made in the social evaluation of the welfare of the presently living generation with that of future generations and does not emphasize the capacity for many social evaluation criteria (including pure utilitarianism and Leximin) to ’proliferate’ from the present generation to any larger set of generations. Our results concerning the orderings generated by such proliferating rules are compared to characterisations already given in the literature.
