The social discussion necessary for full participation in politics must be maintained by a system of interest groups and political parties primarily devoted to deliberation. We saw in the last chapter that social discussion is their primary function in a properly ordered democracy. Here we will ask what this system must be like for it to advance equally the interests of all citizens in society. Recall the example in Chapter 2 of someone who has an automobile but has no idea where to go with the car. Such a person might as well not have a car at all. He is powerless to achieve anything of significance to himself. If one gave him an automobile and did the same for someone else but in addition supplied the other with the means for determining what her interests are and how to achieve them, we would be doing a lot more of significance for her than for the first. Inequality of understanding is as serious as inequality in other means for advancing one's interests.
In democracy, if citizens have the right to vote but lack the means for discovering the purposes to be achieved in voting, then they have little of value. These means are the cognitive conditions of citizenship. And when the conditions for discovering their interests and how to achieve them are available to some and not to others, we have severe political inequality. Political equality, therefore, implies