The making of mistakes by organisms and other living systems is a theoretically and empirically unifying feature of biological investigation. Mistake theory is a rigorous and experimentally productive way of understanding this widespread phenomenon. It does, however, run up against the long-standing ‘functions’ debate in philosophy of biology. Against the objection that mistakes are just a kind of malfunction, and that without a position on functions there can be no theory of mistakes, we reply that this is to misunderstand the theory. In this paper we set out the basic concepts of mistake theory and then argue that mistakes are a distinctive phenomenon in their own right, not just a kind of malfunction.

To the extent that dualism is even taken to be a serious option in contemporary discussions of personal identity and the philosophy of mind, it is almost exclusively either Cartesian dualism or property dualism that is considered. The more traditional dualism defended by Aristotelians and Thomists, what I call hylemorphic dualism, has only received scattered attention. In this essay I set out the main lines of the hylemorphic dualist position, with particular reference to personal identity. First I argue that overemphasis of the problem of consciousness has had an unhealthy effect on recent debate, claiming instead that we should emphasize the concept of form. Then I bring in the concept of identity by means of the notion of substantial form. I continue by analyzing the relation between form and matter, defending the traditional theses of prime matter and of the unicity of substantial form. I then argue for the immateriality of the substantial form of the human person, viz. the soul, from an account of the human intellect. From this follows the soul's essential independence of matter. Finally, although the soul is the immaterial bearer of personal identity, that identity is still the identity of an essentially embodied being. I explain how these ideas are to be reconciled.

There are a number of ways in which a person can share the guilt of another's wrongdoing. He might advise it, command it or consent to it. He might provoke it, praise it, flatter the wrongdoer, or conceal the wrong. He might stay silent when there is a clear duty to denounce the wrong or its perpetrator; or he might positively defend the wrong done. Finally, he might actively participate or cooperate in the wrongdoing. These various activities, apart from cooperation, typically occur before or after the commission of the wrong itself, only provocation being essentially before the fact. As such they fall into the categories of seduction or comfort, seduction being essentially pre-commission and comfort post-commission. In seduction (mutatis mutandis for comfort), the seducer typically leads another into doing wrong who has not definitely made up his mind. He does not assist in the commission, but he leads to its occurring. If the principal (as I will call the one who commits the wrong) has made up his mind, actions which might otherwise amount to seduction are best characterized as amounting to scandal, since they do not lead to wrong but reinforce the principal in his wrongful intent or provide to third parties a bad example since they connote approval of the principal's action. Closely related to the concept of seduction is that of solicitation, though perhaps these are best thought of as two aspects of the same kind of activity. Seduction can be thought of as a strong form of inducement to wrong, typified by command, counsel (where the seducer knows the advice is likely to be relied upon) and enticement through praise or provocation. Solicitation is a softer form of inducement typically involving requests, appeals, and invitations. Whereas the seducer or solicitor leads another into wrong but does not assist in its commission, the co-operator does not lead the principal into wrong but assists in its commission.

Freedom of belief is one of the entrenched values in modern society. Interpreted as the right not to be coerced into believing something, it is surely correct. But most people take it to mean that there is a right to false belief, a right to be wrong. People think that freedom of thought is a good thing, and this must include the freedom to make mistakes. It is also often thought that making mistakes is a life-enhancing and essential part of personal development. I argue that these ideas are false. Beginning with an examination of the basic good of truth, and making comparisons with other goods like health and friendship, I argue that there is a duty to believe only the truth, which thus logically excludes the right also to believe falsehood. I distinguish between the strict wrongness of false belief and the fact that, because of our epistemic limitations, we are not always to be blamed for our false beliefs. Even in the case of those beliefs which are involuntary, there is no right to have them if they are false, even though we are not to be blamed for having them. The right to be wrong, I conclude, is a modern myth.

On 8 February BBC 1 broadcast a programme on the work of Dr. Robert J. White, the American neurologist based in Cleveland, who is world-renowned for his experiments, which he calls ‘body transplants’, in which the body of one monkey is transplanted onto the head of another, through a joining of the carotid arteries and jugular veins, and a clamping together of the two spinal columns. In his most successful experiment, the creature remained alive for seven days, though it was paralysed from the neck down. A photograph showed it lying down, its face contorted in a grimace.

Hundreds of such experiments, involving primates of all sorts, dogs, cats, and various other animals, have been carried out in many countries, notably the People’s Republic of China and the Soviet Union. Dr. White has been showered with awards by his peers, both for his research and for his work with brain-damaged human accident victims. At the same time he is vilified by animal rights campaigners.

He says he can ‘understand’ why some people feel outraged at his experiments and his proposals for further research; people also felt outraged at the thought of kidney and heart transplants—but they are now commonplace. True, he admits, the brain is different, as it seems bound up with the very existence of a person in the way that their heart or kidneys do not, but as long as helping human life is the goal, there is no reason why the brain should not also be treated as transplantable, either with its original head, or into another brainless head (though the latter operation has never succeeded and is technically much more difficult).