 True beliefs are in general suppressed because, though they are true, they are thought to be false. To assume that because one thinks a view is false, it should be suppressed, Mill argues, is to assume infallibility for one’s beliefs. Human beings, though, are not creatures capable of infallible knowledge. Mill’s empiricism leads him to believe that we do not have direct a priori insight into the truth, and that all of our beliefs must remain open to revision in light of further observation. As such, discussion must remain open—even on issues which we think securely established. It might be argued, he observes, that certain true beliefs should be suppressed because, although true, they are thought to be harmful. But to argue that we should suppress a view because it is harmful would either be to assume infallibility on its status as harmful, or to allow debate on that question—which in turn must involve debate on the substantive issue itself. Opinions belonging to case (i) therefore ought to not to be suppressed.