For Comte, the coincidence of individual and collective perfection in the formation of a social body harmonised by love occurs only at the end of a long history. Nevertheless, this summum bonum is more than a regulative ideal, because, as in other grand narratives of progress, it finally does arrive, making visible, indeed, the logic of the process that had propelled it into being. Positivist principles, however, eschewed explanation in terms of final causes, and indeed explanation through causes at all. For Comte, then, demonstrating the necessary actualisation of social perfection required an inductive basis. It was a matter of ‘instituting a true liaison between the historical facts’ (v:8), together with the structural regularities by which these were always mediated.

This did not exempt Comte's construct from the charge by Durkheim, for example, that it was itself metaphysical, identifying ‘historical development with an idea he already had of it’, so that ‘the facts seem to have reality only through the ideas which are their germ’ (1964:19—20). At first sight, Comte's story about how l'homme becomes l'Humanité is metaphysical in an almost classic sense. It seems to unfold as an absolute idealism in which the logic of history is the logic of (the maturation and coming into self-possession of) mind itself. In his first version, in volume five of Philosophie positive, pride of place is given to the Law of Three Stages.