Copi, Quine and van Heijenoort have each claimed that there are two fundamentally different kinds of logical paradox; namely, genuine paradoxes like Russell's and pseudo-paradoxes like the Barber of Seville. I want to contest this claim and will present my case in three stages. Firstly, I will characterize the logical paradoxes; state standard versions of three of them; and demonstrate that a symbolic formulation of each leads to a formal contradiction. Secondly, I will discuss the reasons Copi, Quine and van Heijenoort have given for the distinction between genuine and pseudo-paradoxes. Thirdly, I will attempt to explain why there is no such class as the class of all and only those classes which are not members of themselves.

It is increasingly fashionable to attack McTaggart's arguments about the Unreality of Time with a minimum of attention to what he was trying to establish. Those who have only read his one still famous paper ‘The Unreality of Time’ [III] are too likely to assume from professional philosophers' current counter-arguments that the man was a sceptic with only a single (negative) idea in his head, rather than an ingenious, constructive metaphysician. Since so much formal and informal analysis has been directed against so few of McTaggart's comments on Time, and mainly against his destructive claim that the vulgar concept of Time requires as explicans an incoherent ‘A-series’ of becomings with ever-shifted pasts, presents and futures, perhaps it is time to encourage some redirection of analytical assessment to what he was arguing for. I say this not only for historical reasons, though I shall draw historical comparisons, but because rationally assessing what McTaggart really denies about Time may require some serious interest in what he so interestingly asserts about our experience of what we call ‘Time’. Trousers, pace Austin, normally have one wearer but two legs. If McTaggart's negative points deserve such a plethora of analysis, then the positive view needs attention or the analysis is ill-aimed.

When a normative moral theory collides with our beliefs, we must change either our beliefs or our theory. It is not always clear which we should change; but it is clear that we must change something. I shall consider two collisions between utilitarianism and what we believe, or are supposed to believe. About the first collision, I am going to say that the belief is false and that therefore there is no call to change utilitarianism. About the second, I am going to say that if the belief is true, utilitarianism cannot be changed to accommodate it; I shall leave it open, though, whether the belief is true. The two collisions are related, though different. They both concern the utilitarian thesis about self-sacrifice.

The distinction between private immorality and public indecency plays a significant and perhaps a crucial role in H. L. A. Hart's argument in Law, Liberty, and Morality. This distinction, and the uses to which he puts it, have, however, been largely overshadowed in the ‘debate’ between Professor Hart and Lord Devlin which has centred around such ‘great’ questions as whether a shared morality is necessary for a society. I shall argue that Hart's position, in so far as it is based on that distinction, is quite untenable, and that even if it were to be a possible position, it would none the less be incompatible with the sort of ‘libertarian’ view of society expressed by John Stuart Mill, whose ‘spirit’, at least, Hart believes himself to be defending.