Roman Law.—In the Roman jurisprudence its consequences were very fully developed, and the provisions and terminology of that system have largely affected the subsequent legal treatment of the subject. Its leading principles were simple and well marked. The insane person having no intelligent will, and being thus incapable of consent or voluntary action, could acquire no right and incur no responsibility by his own acts (see Sohm’s Inst. Roman Law, 3rd ed. pp. 216, 217, 219); his person and property were placed after inquiry by the magistrate under the control of a curator, who was empowered and bound to manage the property of the lunatic on his behalf (Sohm, p. 513; Hunter, Roman Law, pp. 732-735). The different terms by which the insane were known, such as demens, furiosus, fatuus, although no doubt signifying different types of insanity, did not in Roman law infer any difference of legal treatment. They were popular names, which all denoted the complete deprivation of reason.
Medieval Law.—During the middle ages the insane were little protected. Their legal acts were annulled, and their property placed under control, but little or no attempt was made to supervise their personal treatment. In England the wardship of idiots and lunatics, which was annexed before the reign of Edward II. to the king’s prerogative, had regard chiefly to the control of their lands and estates, and was only gradually elaborated into the systematic control of their persons and property now exercised under the jurisdiction in lunacy. Those whose means were insignificant were left to the care of their relations or to charity. In criminal law the plea of insanity was unavailing except in extreme cases. About the beginning of the 19th century a very considerable change commenced. The public attention was strongly attracted to the miserable condition of the insane incarcerated in asylums without any efficient check or inspection; and at the same time the medical knowledge of insanity entered on a new phase. The possibility and advantages of a better treatment of insanity were illustrated by eminent physicians, Philippe Pinel in France, H. Tuke in England, Bond, B. Rush and I. Ray in the United States; its physical origin became generally accepted; its mental phenomena were more carefully observed, and its relation was established to other mental conditions.
Modern Law.—From this period we date the commencement of legislation such as that known in England as the Lunacy Acts, which aimed at the regulation and control of all constraint applied to the insane. Hitherto, the criteria of insanity had been very rude, and the evidence was generally of a loose and popular character; but, whenever it was fully recognized that insanity was a disease with which physicians who had studied the subject were peculiarly conversant, expert evidence obtained increased importance, and from this time became prominent in every case. The newer medical views of insanity were thus brought into contact with the old narrow conception of the law courts, and a controversy arose in the field of criminal law which in England, at least, still continues.
Relations between Insanity and Law.—The fact of insanity may operate in law—(1) by excluding responsibility for crime; (2) by invalidating legal acts; (3) by affording ground for depriving the insane person by a legal process of the control of his person and property; or (4) by affording ground for putting him under restraint.
Legal Terminology.—Before proceeding, however, to deal with these matters in succession, it may be desirable to say something with regard to the chief legal terms respecting persons suffering under mental disabilities. The subject is now of less importance than formerly, because the modern tendency of the law is to determine the capacity or responsibility of a person alleged to be insane by considering it with reference to the particular matter or class of matters which brings his mental condition sub judice. But the literature of the law of lunacy cannot be clearly understood unless the distinctions between the different terms employed to describe the insane are kept in view. The term non compos mentis is as old as the statute De praerogativa regis (1325), and is used sometimes, as in that statute, to indicate a species contrasted with idiot, sometimes (e.g. in Co. Litt. 246 (b)) as a genus, and afterwards, chiefly in statutes relating to the insane, in connexion with the terms “idiot” and “lunatic” as a word ejusdem generis. The word “idiot” (Gr. ἴδιος, a private person, one who does not hold any public office, and ἰδιώτης, an ignorant and illiterate person) appears in the statute De praerogativa regis as fatuus naturalis, and it is placed in contradistinction to non compos mentis. The “idiot” is defined by Sir E. Coke (4 Rep. 124 (b)) as one who from his nativity, by a perpetual infirmity, is non compos mentis, and Sir M. Hale (Pleas of the Crown, i. 29) describes idiocy as “fatuity a nativitate vel dementia naturalis.” In early times various artificial criteria of idiocy were suggested. Fitzherbert’s test was the capacity of the alleged idiot to count twenty pence, or tell his age, or who were his father and mother (De natura brevium, 233). Swinburne proposed as a criterion of capacity, inter alia, to measure a yard of cloth or name the days in the week (Testaments, 42). Hale propounded the sounder view that “idiocy or not is a question of fact triable by jury and sometimes by inspection” (Pleas of the Crown, i. 29). The legal incidents of idiocy were at one time distinct in an important particular from those of lunacy. Under the statute De praerogativa regis the king was to have the rents and profits of an idiot’s lands to his own use during the life of the idiot, subject merely to an obligation to provide him with necessaries. In the case of the lunatic the king was a trustee, holding his lands and tenements for his benefit and that of his family. It was on account of this difference in the legal consequences of the two states that on inquisitions distinct writs, one de idiota inquirendo, the other de lunatico inquirendo, were framed for each of them. But juries avoided finding a verdict of idiocy wherever they could, and the writ de idiota inquirendo fell into desuetude. A further blow was struck at the distinction when it came to be recognized even by the legislature (see the Idiots Act 1886) that idiots are capable of being educated and trained, and it was practically abolished when the Lunacy Regulation Act 1862, in a provision reproduced in substance in the Lunacy Act 1890, limited the evidence admissible in proof of unsoundness of mind on an inquisition (without special leave of the Master trying the case) to a period of two years before the date of the inquiry, and raised a uniform issue, viz. the state of mind of the alleged lunatic at the time when the inquisition is held.
The term “lunatic,” derived from the Latin luna in consequence of the notion that the moon had an influence on mental disorders,[1] does not appear in the statute-book till the time of Henry VIII. (1541). Coke defines a lunatic as a “person who has sometimes his understanding and sometimes not, qui gaudet lucidis intervallis, and therefore he is called non compos mentis so long as he has not understanding” (Co. Litt. 247 (a), 4 Rep. 124 (b)). Hale defines “lunacy” as “interpolated” (i.e. intermittent) dementia accidentalis vel adventitia, whether total or (a description, it will be observed, of “partial insanity”) quoad hoc vel illud (Pleas of the Crown, i. 29). In modern times, the word “lunacy” has lost its former precise signification. It is employed sometimes in the strict sense, sometimes in contradistinction to “idiocy” or “imbecility”; once at least—viz. in the Lunacy Act 1890—as including “idiot”; and frequently in conjunction with the vague terms “unsound mind” (non-sane memory) and “insane.” Section 116 of the Lunacy Act 1890 has by implication extended the meaning of the term lunacy so as to include for certain purposes the incapacity of a person to manage his affairs through mental infirmity arising from disease or age. “Imbecility” is a state of mental weakness “between the limits of absolute idiocy on the one hand and of perfect capacity on the other” (see 1 Haggard, Eccles. Rep. p. 401).
1. The Criminal Responsibility of the Insane.—The law as to the criminal responsibility of the insane has pursued in England a curious course of development. The views of Coke and Hale give the best exposition of it in the 17th century. Both were agreed that in criminal causes the act and wrong of a madman shall not be imputed to him; both distinguished, although in different language, between dementia naturalis (or a nativitate) and dementia accidentalis or adventitia; and the main points in which the writings of Hale mark an advance on those of Coke are in the elaboration by the former of the doctrine of “partial insanity,” and his adoption of the level of understanding of a child of fourteen years of age as the test of responsibility in criminal cases (Pleas of the Crown, i. 29, 30; and see Co. 4 Rep. 124 (b)). In the 18th century a test, still more unsatisfactory than this “child of fourteen” theory, with its identification of “healthy immaturity” with “diseased maturity” (Steph. Hist. Crim. Law, ii. 150), was prescribed. On the trial of Edward Arnold in 1723 for firing at and wounding Lord Onslow, Mr Justice Tracy told the jury that “a prisoner, in order to be acquitted on the ground of insanity, must be a man that is totally deprived of his understanding and memory, and doth not know what he is doing, no more than an infant, than a brute or wild beast.” In the beginning of the 19th century a fresh statement of the test of criminal responsibility in mental disease was attempted. On the trial of Hadfield for shooting at George III. in Drury Lane Theatre on 15th May 1800, Lord Chief Justice Kenyon charged the jury in the following terms: “If a man is in a deranged state of mind at the time, he is not criminally answerable for his acts; but the material part of the case is whether at the very time when the act was committed the man’s mind was sane.” The practical effect of this ruling, had it been followed, would have been to make the question of the amenability of persons alleged to be insane to the criminal law very much one of fact, to be answered by juries according to the particular circumstances of each case, and without being aided or embarrassed by any rigid external standard. But in 1812, on the trial of Bellingham for the murder of Mr Perceval, the First Lord of the Treasury, Sir James Mansfield propounded yet another criterion of criminal responsibility in mental disease, viz. whether a prisoner has, at the time of committing an offence, a sufficient degree of capacity to distinguish between good and evil. The objection to this doctrine consisted in the fact, to which the writings of Continental and American jurists soon afterwards began to give prominence, that there are very many lunatics whose general ideas on the subject of right and wrong are quite unexceptionable, but who are yet unable, in consequence of delusions, to perceive the wrongness of particular Macnaughton’s Case. acts. Sir James Mansfield’s statement of the law was discredited in the case (4 State Tri. (n.s.) 847; 10 Cl. and Fin. 200) of Daniel Macnaughton, who was tried in March 1843, before Chief Justice Tindal, Mr Justice Williams and Mr Justice Coleridge, for the murder of Mr Drummond, the private secretary of Sir Robert Peel. Mr (afterwards Lord Chief Justice) Cockburn, who defended the prisoner, used Hale’s doctrine of partial insanity as the foundation of the defence, and secured an acquittal, Chief Justice Tindal telling the jury that the question was whether Macnaughton was capable of distinguishing right from wrong with respect to the act with which he stood charged. This judicial approval of the doctrine of partial insanity formed the subject of an animated debate in the House of Lords, and in the end certain questions were put by that House to the judges, and answered by Chief Justice Tindal on behalf of all his colleagues except Mr Justice Maule, who gave independent replies. The answers to those questions are commonly called “The Rules in Macnaughton’s case,” and they still nominally contain the law of England as to the criminal responsibility of the insane. The points affirmed by the Rules that must be noted here are the propositions that knowledge of the nature and quality of the particular criminal act, at the time of its commission, is the test of criminal responsibility, and that delusion is a valid exculpatory plea, when, and only when, the fancies of the insane person, if they had been facts, would have been so. The Rules in Macnaughton’s case are open to serious criticism. They ignore, at least on a literal interpretation, those forms of mental disease which may, for the present purpose, be roughly grouped under the heading “moral insanity,” and in which the moral faculties are more obviously deranged than the mental—the affections and the will, rather than the reason, being apparently disordered. The test propounded with reference to delusions has also been strenuously attacked by medical writers, and especially by Dr Maudsley in his work on Responsibility in Mental Disease, on the ground that it first assumes a man to have a delusion in regard to a particular subject, and then expects and requires him to reason sanely upon it. It may be pointed out, however, that in thus localizing the range of the immunity which insane delusion confers, the criminal law is merely following the course which, mutatis mutandis, the civil law has, with general acceptance, adopted in questions as to the contractual and testamentary capacity of the insane.
The Rules in Macnaughton’s case have, as regards moral insanity, undergone considerable modification. Soon after they were laid down, Sir (then Mr) James Fitz-James Stephen, in an article in the Juridical Papers, i. 67, on the policy of maintaining the existing law as to the criminal responsibility of the insane, foreshadowed the view which he subsequently propounded in his History of the Criminal Law, ii. 163, that no man who was deprived by mental disease of the power of passing a fairly rational judgment on the moral character of an act could be said to “know” its nature and quality within the meaning of the Rules; and it has in recent years been found possible in practice so to manipulate the test of the criminal responsibility which they prescribed as to afford protection to the accused in the by no means infrequent cases of insanity which in its literal interpretation it would leave without excuse.
In Scotland the Rules in Macnaughton’s case are recognized, but, as in England, there is a tendency among judges to adopt a generous construction of them. Mental unsoundness insufficient to bar trial, or to exempt from punishment, may still, it is said, be present in a degree which is regarded as reducing the offence from a higher to a lower category,—a doctrine first practically applied in Scotland, it is believed, in 1867 by Lord Deas; and the fact that a prisoner is of weak or ill-regulated mind is often urged with success as a plea in mitigation of punishment. The Indian Penal Code (Act XLV. of 1860, § 84) expressly adopts the English test of criminal responsibility, but the qualifications noted in the case of Scotland have received some measure of judicial acceptance (see Mayne, Crim. Law Ind., 3rd ed., pp. 403-419; Nelson, Ind. Pen. Code, 3rd ed., pp. 135 et seq.). The Rules in Macnaughton’s case have also been adopted in substance in those colonies which have codified the criminal law. The following typical references may be given: 55 and 56 Vict. (Can.) c. 29, § 11; 57 Vict. (N.Z.), No. 56 of 1893, § 23; No. 101 of 1888 (St Lucia), § 50; No. 5 of 1876 (Gold Coast), § 49 (b); No. 2 of 1883, art. 77 (Ceylon); No. 4 of 1871, art. 84 (Straits Settlements). On the other hand, a departure towards a recognition of “moral insanity” is made by the Queensland Criminal Code (No. 9 of 1899), § 27 of which provides that “a person is not criminally responsible for an act” if at the time of doing it “he is in such a state of mental disease ... as to deprive him ... of capacity to control his actions”: and the law has been defined in the same sense in the Cape of Good Hope in the case of Queen v. Hay (1899, 16 S.C.R. 290). The Rules were rapidly reproduced in the United States, but the modern trend of American judicial opinion is adverse to them (see Clevenger, Med. Jur. of Ins. p. 125; Parsons v. State (1887) 81 Ala. 577). On the Continent of Europe moral insanity and irresistible impulse are freely recognized as exculpatory pleas (see the French Code Penal, § 64; Belgian Code Penal, § 71; German Penal Code, § 51; Italian Penal Code, §§ 46, 47).
Not only is insanity at the time of the commission of an offence a valid exculpatory plea, but supervening insanity stays the action of the criminal law at every stage from arrest up to punishment. High treason was formerly an exception, but the statute making it so (33 Hen. VIII. c. 20) was repealed in the time of Philip and Mary. The Home Secretary has power, under the Criminal Lunatics Act 1884 to order by warrant the removal of a prisoner, certified to be insane, to a lunatic asylum, before[2] trial or after trial, whether under sentence of death or not. Prisoners dealt with under these provisions are styled “Secretary of State’s lunatics.” On the other hand, a prisoner who on arraignment appears, or is found by the jury to be unfit to plead, or who is found “guilty but insane” at the time of committing the offence—a verdict substituted by the Trial of Lunatics Act 1883 for the old verdict of “acquitted on the ground of insanity,” in the hope that the formal conviction recorded in the new finding might have a deterrent effect on the mentally unstable—is committed to a criminal lunatic asylum by the order of the judge trying the case, to be detained there “during the king’s pleasure.” Lunatics of this class are called “king’s pleasure lunatics.” There was no doubt at common law as to the power of the courts to order the detention of criminal lunatics in safe custody, but, prior to 1800, the practice was varying and uncertain. On the acquittal of Hadfield, however, in that year for the attempted murder of George III., a question arose as to the provision which was to be made for his detention, and the Criminal Lunatics Act 1800, part of which is still in force, was passed to affirm the law on the subject.