Margaret Gilbert

May social unity - the unity of a society or social group - be a matter of sharing values? Political philosophers disagree on this topic. Kymlicka answers: No. Devlin and Rawls answer: Yes. It is argued that given one common 'summative' account of sharing values a negative answer is correct. A positive answer is correct, however, given the plural subject account of sharing values. Given this account, those who share values are unified in a substantial way by their participation in a joint commitment. Some consequences of such sharing of values for the liberty of the people involved are noted.

Collective action is interpreted as a matter of people doing something together, and it is assumed that this involves their having a collective intention to do that thing together. The account of collective intention for which the author has argued elsewhere is presented. In terms that are explained, the parties are jointly committed to intend as a body that such-and-such. Collective action problems in the sense of rational choice theory—problems such as the various forms of coordination problem and the prisoner’s dilemma—are then considered. An explanation is given of how, when such a problem is interpreted in terms of the parties’ inclinations, a suitable collective intention resolves the problem for agents who are rational in a broad sense other than the technical sense of game theory. Key Words: rationality • collective action • collective intention • joint commitment.

This paper criticises a line of argument adopted by peter winch, Karl popper, And others, To the effect that the course of human history cannot be predicted. On this view it is impossible to predict in a particularly detailed way certain events ('original acts') on which important social developments depend. We analyze the argument, Showing that one version fails: original acts are in principle predictable in the relevant way. A cogent version is presented; this requires a special definition for 'original act'. But, We claim, Social developments do not depend on original acts so defined. We argue separately for the possibility of a person, Or a scientific community, Predicting his or its own original acts.