This article examines how a liberal public morality can be most successfully defended against perfectionism. First of all the five most important liberal arguments for freedom are taken from what is called the liberal canon: a number of characteristic works of John Locke, Immanuel Kant, John Stuart Mill, Isaiah Berlin, Joseph Raz, Ronald Dworkin, and John Rawls. These five arguments are identified as: social and political realism, respect for autonomy, fallibility of ideas, pluralism, and respect for reasonableness. Next, the persuasiveness of these arguments is assessed, starting with the argument of respect for reasonableness, which is at the heart of Rawls’s political liberalism. It is concluded that in itself this argument is not strong enough to persuade perfectionists. A powerful defence of a liberal public morality needs the other arguments for freedom as well. Finally, the paper outlines how these other arguments can strengthen the argument of respect for reasonableness in a coherent manner.

André Köbben’s academic career spans sixty years and he’s still going strong – just because he likes it so much. Doing research by himself, which took him for longer periods to Ivory Coast and Surinam apart from studying conflicts in the Netherlands, but also analysing research by others. He has always been interested in questions of ‘rule’ and ‘reality’: the discrepancy between what people say they do and what they actually are doing. He probed tribal disputes among the Agni, the Bete and the Djoeka, but also conflicting interests between managers ordering research and researchers producing unwelcome results. He is preparing a book on academic fraud.