  Turn now to the assumption of self-interest. In generalizing from the motive of self-interest to the explanation and even justification of actions and institutions, Hobbes wished to reduce political theory to an analog of geometry or physics, so that it would be a deductive science. All of the statements of the logic of collective action above are grounded in an assumption of the self-interested incentives of the actors. When the number of members of a group that would benefit from collective action is small enough, we might expect cooperation that results from extensive interaction, mutual monitoring, and even commitments to each other that trump or block narrowly self-interested actions. But when the group is very large, free riding is often clearly in the interest of most and perhaps all members.