Abstract
It is argued against McCloskey (1) that the restrictions on freedom of opinion which Mill is alleged to concede are not in fact departures from his general principle; (2) that Mill's infallibility argument is not quite as McCloskey interprets it, but makes the point that it is possible to have rationally grounded opinions only in a society in which free enquiry is encouraged, and that McCloskey's counter-examples fail because they presuppose such a society; (3) that Mill attaches more importance than McCloskey allows to the argument that opinions arc valueless unless rationally held and that his conception of rationality and self-development differs from McCloskey's; (4) that there is a general principle, which McCloskey has not refuted, namely that an atmosphere of free enquiry is hard to maintain, and that any suppression, even one apparently justified, will have the indirect effect of helping to destroy that atmosphere, and is consequently likely to do more harm than good.