Persons are not separate objects in space. They are centres of orientation to the world. These different centres and their worlds are not islands, but the nature of their reciprocal influence and interaction has always been difficult to incorporate adequately into interpersonal theory. By considering the person from the beginning always in terms of one of his group metamorphoses, without according any theoretical or methodological priority to the person as an abstracted ego extrapolated from his interhuman context, there is some hope that a radical advance in our thinking in this respect is possible.

This is what Sartre in his most recent work, Critique de la Raison Dialectique, seems to me to have already begun to achieve. The theory therein has been of immense help to me in my own researches, both practically and specifically into families, and more theoretically and generally.

In the following I shall give an account of two theoretical polarities developed by Sartre in the Critique, namely, praxis and process, and series and nexus,footnote1 using the family as a point of concrete reference.

Events, occurrences, happenings, may be deeds done by doers, or they may be the outcome of, or parts of, a continuous series of operations that have no agent as their author.

In the first case, Sartre speaks of such events as the outcome of praxis: in the second case, as the outcome of process.