This excellent study deals thoroughly with three of the most difficult aspects of the concepts of criminal responsibility. It is concerned principally with the mental states of the title and how the courts establish and deal with them.

As is well-known, the traditional legal background divides crimes into those that require mens rea (literally, a guilty mind) and those that merely require proof that the accused has committed the criminal act. That traditional distinction, like so much else in the legal system, is clear but by no means free of difficulty. The three mental states considered in this study are equally liable to confuse, especially as they have differing impacts upon the establishment of guilt, as well as being relevant to the choice of the appropriate sentence to be determined by the court where guilt has been established.

Much of legal doctrine is more like the deck of an ocean liner than dry land — there is much beneath its shifting surface. Since the mental states that have to be considered deal with the mind of the accused they clearly are difficult to determine. Many cases rely on psychiatry to give important insights that may assist both in the determination of guilt and, where there is a conviction, the appropriate sentence.

The mental state of an accused is of particular importance to the question of guilt in serious crimes. There are, however, vast numbers of crimes and offences defined in statute law that do not require that mental element. But in such cases the mental state of the accused will, very often, be an important consideration when it comes to the determination of sentence. It may mitigate the crime (or on occasion, stress its wickedness) and so affect the sentence imposed by the court. Usually it will lead to a reduction of the usual tariff or to the use of other forms of disposal such as a period of probation or, where the mental state is appropriate, detention in hospital for the protection of both the individual concerned and society in general.

The mental element does not arise in absolute offences, which are defined by statute as solely requiring the prohibited act. This arises from common sense, since the admission of the concept of mens rea to minor motoring offences, even if sensible, would be a nightmare for the courts. In these offences, once the necessary acts are proved, the mind of the accused is not relevant to the question of guilt — the sole question is ‘Did he do it?’, as most motorists tend to find out at some time or another. Of course, it will be a factor in the determination of severity of sentence.

The text is plainly intended for the academic rather than the general reader, although the attention to detail is accompanied by an excellent clarity of style. Buchanan, a forensic psychologist at the Institute of Psychiatry in London, has written a comprehensive study on a topic of particular importance to forensic psychiatrists or those having fairly frequent contact with the courts.