cently, no one could tell whether or not they are precisely equal, or, if unequal, on which side there is an excess. The births being the physical result of physical antecedents, it was clearly seen that the laws of the births must be in those antecedents; that is to say, that the causes of the proportion of the sexes must reside in the parents themselves. Under these circumstances, the question arose, if it was not possible to elucidate this difficulty by our knowledge of animal physiology; for it was plausibly said, "Since physiology is a study of the laws of the body," and since all births are products resulting from the body, it follows that if we know the laws of the body, we shall know the laws of the birth." This was the view taken by physiologists of our origin; and this is precisely the view taken by metaphysicians of our history. Both parties believed that it was possible at once to rise to the cause of the phenomenon, and by On this question, a variety of conflicting statements may be seen in the older writers. Goodman, early in the seventeenth century, supposed that more females were born than males. Southey's Commonplace Book, third series, p. 696. Turgot (Euvres, vol. ii. p. 247) rightly says, "il naît un peu plus d'hommes que de femmes :" but the evidence was too incomplete to make this more than a lucky guess; and I find that even Herder, writing in 1785, takes for granted that the proportion was about equal: "ein ziemliches Gleichmass in den Geburten beider Geschlechter" (Ideen zur Geschichte, vol. ii. p. 149), and was sometimes in favour of girls, "ja die Nachrichten mehrerer Reisenden machen es wahrscheinlich, dass in manchen dieser Gegenden wirklich mehr Töchter als Söhne geboren werden." 3 A question, indeed, has been raised as to the influence exercised by the state of the mind during the period of orgasm. But whatever this influence may be, it can only affect the subsequent birth through and by physical antecedents, which in every case must be regarded as the proximate cause. If, therefore, the influence were proved to exist, we should still have to search for physical laws: though such laws would of course be considered merely as secondary ones, resolvable into some higher generalization. * Some writers treat physiology as a study of the laws of life. But this, looking at the subject as it now stands, is far too bold a step, and several branches of knowledge will have to be raised from their present empirical state, before the phenomena of life can be scientifically investigated. The more rational mode seems to be, to consider physiology and anatomy as correlative: the first forming the dynamical, and the second forming the statical part of the study of organic structure. Voulez-vous savoir de quoi dépend le sexe des enfants? Fernel vous répond, sur la foi des anciens, qu'il dépend des qualités de la semence du père et de la mère.' Renouard, Histoire de la Médecine, Paris, 1846, vol. ii. p. 106: see also, at p. 185, the opinion of Hippocrates, adopted by Galen; and similar views in Lepelletier, Physiologie Médicale, vol. iv. p. 332, and Sprengel, Hist. de la Médecine, vol. i. pp. 252, 310, vol. ii. p. 115, vol. iv. p. 62. For further information as to the opinions which have been held respecting the origin of sexes, see Beausobre, Histoire de Manichée, vol. ii. p. 417; Asiatic Researches, vol. iii. pp. 358, 361; Vishnu Purana, p. 349; Works of Sir William Jones, vol. iii. p. 126; Ritter's History of Ancient Philosophy, vol. iii. p. 191; Denham and Clapperton's Africa, pp. 323, 324; Maintenon, Letters Inédites, vol. ii. p. 62; and the view of Hohl (Burdach's Physiologie, vol. ii. p. 472), "que les femmes chez lesquelles prédomine le système artériel procréent des garçons, au lieu que celles dont le système veineux a la prédominance mettent au monde des filles." According to Anaxagoras, the question was extremely simple; καὶ ἄῤῥενα μὲν ἀπὸ τῶν δεξιῶν, θήλεα δὲ ἀπὸ τῶν ἀριστερῶν. Diog. Laert. ii. 9, vol. i. p. 85. studying its laws predict the phenomenon itself. The physiologist said, "By studying individual bodies, and thus ascertaining the laws which regulate the union of the parents, I will discover the proportion of the sexes, because the proportion is merely the result to which the union gives rise." Just in the same way, the metaphysician says, "By studying individual minds, I will ascertain the laws which govern their movements; and in that way I will predict the movements of mankind, which are obviously compounded of the individual movements." These are the expectations which have been confidently held out, by physiologists respecting the laws of the sexes, and by metaphysicians respecting the laws of history. Towards the fulfilment, however, of these promises, the metaphysicians have done absolutely nothing; nor have the physiologists been more successful, although their views have the support of anatomy, which admits of the employment of direct experiment, a resource unknown to metaphysics. But towards settling the present question, all this availed them nothing; and physiologists are not yet possessed of a single fact which throws any light on this problem: Is the number of male births equal to female births, is it greater, or is it less? These are questions to which all the resources of physiologists, from Aristotle down to our own time, afford no means of reply." "Le métaphysicien se voit comme la source de l'évidence et le confident de la nature: Moi seul, dit-il, je puis généraliser les idées, et découvrir le germe des événements qui se développent journellement dans le monde physique et moral; et c'est par moi seul que l'homme peut être éclairé." Helvetius de l'Esprit, vol. i. p. 86. Compare Herder, Ideen zur Geschichte der Menschheit, vol. ii. p. 105. Thus too M. Cousin (Hist. de la Philosophie, II. série, vol. i. p. 131) says, "Le fait de la conscience transporté de l'individu dans l'espèce et dans l'histoire, est la clef de tous les développements de l'humanité." Considering the very long period during which physiology has been studied, it is remarkable how little the physiologists have contributed towards the great and final object of all science, namely the power of predicting events. To me it appears that the two principal causes of this are, the backwardness of chemistry, and the still extremely imperfect state of the microscope, which even now is so inaccurate an instrument, that when a high power is employed, little confidence can be placed in it; and the examination, for instance, of the spermatozoa has led to the most contradictory results. In regard to chemistry, MM. Robin and Verdeil, in their recent great work, have ably proved what manifold relations there are between it and the further progress of our knowledge of the animal frame; though I venture to think that these eminent writers have shown occasionally an undue disposition to limit the application of chemical laws to physiological phenomena. See Robin et Verdeil, Chimie Anatomique et Physiologique, Paris, 1853, vol. i. pp. 20, 34, 167, 337, 338, 437, 661, vol. ii. pp. 136, 137, 508, vol. iii. pp. 135, 144, 183, 281, 283, 351, 547. The increasing tendency of chemistry to bring under its control what are often supposed to be purely organic phenomena, is noticed cautiously in Turner's Chemistry, vol. ii. p. 1308, London, 1847; and boldly in Liebig's Letters on Chemistry, 1851, pp. 250, 251. The connexion between chemistry and physiology is touched on rather too hastily in Bouilland, Philosophie Médicale, pp. 160, 257; Broussais, Examen des Doctrines Médicales, vol. iii. p. 166; Brodie's Lectures on Pathology, p. 48; Henle, Traité d'Anatomie, vol. i. pp. 25, 26; Feuchtersleben's Medical Psychology, p. 88; but better in Holland's Medical Notes, 1839, p. 270, a thoughtful and And yet at the present day we, by the employment of what now seems a very natural method, are possessed of a truth which the united abilities of a long series of eminent men failed to discover. By the simple expedient of registering the number of births and their sexes; by extending this registration over several years, in different countries, we have been able to eliminate all casual disturbances, and ascertain the existence of a law which, expressed in round numbers, is, that for every twenty girls there are born twenty-one boys and we may confidently say, that although the operations of this law are of course liable to constant aberrations, the law itself is so powerful, that we know of no country in which during a single year the male births have not been greater than the female ones. The importance and the beautiful regularity of this law, make us regret that it still remains an empirical truth, not having yet been connected with the physical phenomena by which its operations are caused.' But this is immaterial to my present suggestive work. On the necessity of chemistry for increasing our knowledge of embryology, compare Wagner's Physiology, pp. 131, 132 note, with Burdach, Traité de Physiologie, vol. iv. pp. 59, 168. It used to be supposed that some of the eastern countries formed an exception to this; but more precise observations have contradicted the loose statements of the earlier travellers, and in no part of the world, so far as our knowledge extends, are more girls born than boys; while in every part of the world for which we have statistical returns, there is a slight excess on the side of male births. Compare Marsden's History of Sumatra, p. 234; Raffles' History of Java, vol. i. pp. 81, 82; Sykes on the Statistics of the Deccan, in Reports of British Association, vol. vi. pp. 246, 261, 262; Niebuhr, Description de l'Arabie, p. 63; Humboldt, Nouv. Espagne, vol. i. p. 139; M William, Medical History of Expedition to the Niger, p. 113; Elliotson's Human Physiology, p. 795; Thomson's Hist. of Royal Society, p. 531; Sadler's Law of Population, vol. i. pp. 507, 511, vol. ii. pp. 324, 335; Paris and Fonblanque's Medical Jurisprudence, vol. i. p. 259; Journal of Satist. Soc., vol. iii. pp. 263, 264, vol. xvii. pp. 46, 123; Journal of Geographical Soc., vol. xx. p. 17; Fourth Report of British Association, pp. 687, 689, Report for 1842, pp. 144, 145; Transac. of Sections for 1840, p. 174, for 1847, p. 96, for 1849, p. 87; Dufau, Traité de Statistique, pp. 24, 209, 210; Burdach, Traité de Physiologie, vol. ii. pp. 56, 57, 273, 274, 281, vol. v. p. 373; Hawkins's Medical Statistics, pp. 221, 222. In Muller's Physiology, vol. ii. p. 1657, a work of great authority, it is said, that "the causes which determine the sex of the embryo are unknown, although it appears that the relative age of the parents has some influence over the sex of the offspring." That the relative age of the parents does affect the sex of their children, may, from the immense amount of evidence now collected, be considered almost certain; but M. Müller, instead of referring to physiological writers, ought to have mentioned that the statisticians, and not the physiologists, were the first to make this discovery. On this curious question, see Carpenter's Human Physiology, p. 746; Sadler's Law of Population, vol. ii. pp. 333, 336, 342; Journal of Statistical Society, vol. iii. pp. 263, 264. In regard to animals below man, we find from numerous experiments, that among sheep and horses the age of the parents "has a very great general influence upon the sex" of the offspring. Elliotson's Physiology, pp. 708, 709; and see Cuvier, Progrès des Sciences Naturelles, vol. ii. p. 406. As to the relation between the origin of sex and the laws of arrested development, compare Geoffroy Saint Hilaire, Hist. des Anomalies de l'Organisation, vol. ii. pp. 33, 34, 73, vol. iii. p. 278, with Lindley's Botany, vol. ii. p. 81. In Esquirol, Maladies Mentales, vol. i. p. 302, there is a singular case recorded by Lamotte, which would seem to purpose, which is only to notice the method by which the discovery has been made. For this method is obviously analogous to that by which I propose to investigate the operations of the human mind; while the old and unsuccessful method is analogous to that employed by the metaphysicians. As long as physiologists attempted to ascertain the laws of the proportion of sexes by individual experiments, they effected absolutely nothing towards the end they hoped to achieve. But when men became dissatisfied with these individual experiments, and instead of them, began to collect observations less minute, but more comprehensive, then it was that the great law of nature, for which during many centuries they had vainly searched, first became unfolded to their view. Precisely in the same way, as long as the human mind is only studied according to the narrow and contracted method of metaphysicians, we have every reason for thinking that the laws which regulate its movements will remain unknown. If, therefore, we wish to effect any thing of real moment, it becomes necessary that we should discard those old schemes, the insufficiency of which is demonstrated by experience as well as by reason; and that we should substitute in their place such a comprehensive survey of facts as will enable us to eliminate those disturbances which, owing to the impossibility of experiment, we shall never be able to isolate. The desire that I feel to make the preliminary views of this Introduction perfectly clear, is my sole apology for having introduced a digression which, though adding nothing to the strength of the argument, may be found useful as illustrating it, and will at all events enable ordinary readers to appreciate the value of the proposed method. It now remains for us to ascertain the manner in which, by the application of this method, the laws of mental progress may be most easily discovered. If, in the first place, we ask what this progress is, the answer seems very simple that it is a twofold progress, Moral and Intellectual; the first having more immediate relation to our duties, the second to our knowledge. This is a classification which has been frequently laid down, and with which most persons are familiar. And so far as history is a narration of results, there can be no doubt that the division is perfectly accurate. There can be no doubt that a people are not really advancing, if, on the one hand, their increasing ability is accompanied by increasing vice, or if, on the other hand, while they are becoming more virtuous, they likewise become more ignorant. This double movement, moral and intellectual, is essential to connect this question with pathological phenomena, though it is uncertain whether the epilepsy was an effect or a cognate symptom. the very idea of civilization, and includes the entire theory of mental progress. To be willing to perform our duty is the moral part; to know how to perform it is the intellectual part: while the closer these two parts are knit together, the greater the harmony with which they work; and the more accurately the means are adapted to the end, the more completely will the scheme of our life be accomplished, and the more securely shall we lay a foundation for the further advancement of mankind. A question, therefore, now arises of great moment: namely, which of these two parts or elements of mental progress is the more important. For the progress itself being the result of their united action, it becomes necessary to ascertain which of them works more powerfully, in order that we may subordinate the inferior element to the laws of the superior one. If the advance of civilization, and the general happiness of mankind, depend more on their moral feelings than on their intellectual knowledge, we must of course measure the progress of society by those feelings; while if, on the other hand, it depends principally on their knowledge, we must take as our standard the amount and success of their intellectual activity. As soon as we know the relative energy of these two components, we shall treat them according to the usual plan for investigating truth; that is to say, we shall look at the product of their joint action as obeying the laws of the more powerful agent, whose operations are casually disturbed by the inferior laws of the minor agent. In entering into this inquiry, we are met by a preliminary difficulty, arising from the loose and careless manner in which ordinary language is employed on subjects that require the greatest nicety and precision. For the expression, Moral and Intellectual Progress, is suggestive a serious fallacy. In the manner in which it is generally used, it conveys an idea that the moral and intellectual faculties of men are, in the advance of civilization, naturally more acute and more trustworthy than they were formerly. But this, though it may possibly be true, has never been proved. It may be that, owing to some physical causes still unknown, the average capacity of the brain is, if we compare long periods of time, becoming gradually greater; and that therefore the mind, which acts through the brain, is, even independently of education, increasing in aptitude and in the general competence of its views. 10 Such, however, is still our 10 That the natural powers of the human brain are improving because they are capable of transmission, is a favourite doctrine with the followers of Gall, and is adopted by M. A. Comte (Philosophie Positive, vol. iv. pp. 384, 385); who, however, admits that it has never been sufficiently verified: "sans que toutefois l'expérience ait encore suffisamment prononcé." Dr. Prichard, whose habits of thought were very different, seems, nevertheless, inclined to lean in this direction; for his com |