So let me summarize the ways I very much agree with Sen:
- we have to think about actual lives and realized outcomes, not abstract rules and institutions alone. What matters is the substance and outcomes, not just the process.
- we need to have a wider conception of rationality - reasonableness and the test of public discussion and criticism
- impartiality is important, but not everything
- we cannot simply rule out some of the most important questions - of ends, of purpose, of comparing utility across and between people - on methodological grounds.
- many problems of social choice and collective action come about because we restrict the information about people's purposes and preferences too much. The solution to a lot of social problems (including the limits of voting) is a richer set of information.