Is science of comparative politics possible? / Alasdair MacIntyre -- Political theory of scarcity / James Cornford -- Obligation and consent / Hanna Pitkin -- 'Normal' science or political ideology? / Alan Ryan -- Coercion / Robert Nozick -- 'Social meaning' and the explanation of social action / Quentin Skinner -- Identity of the history of ideas / John Dunn -- Negative and positive freedom / Gerald C. MacCallum Jr. -- Why is authority such a problem? / Richard Tuck -- Collective decisions and collective action / James Coleman