INTRODUCTION.

A VARIETY OF CONSIDERATIONS seems to me to render it desirable that I should explain shortly the circumstances under which the following work has been written. On the one hand, for instance, the value of an author's opinion on a given subject necessarily depends on his qualifications for forming and expressing an opinion; which qualifications include the natural bias of his mind, the direction in which his mental qualities have been cultivated, the nature and extent of his opportunities for observation, with the degree to which he has availed himself of his opportunities, the extent and variety of his teaching-in other words, his special experience and aptitude in the investigation of the said subject.

On the other hand, the subject of Mind in the Lower Animals is one that has from time immemorial been regarded, if not studied, from the most different points of view, and one that will doubtless continue to be so regarded. Theologians, metaphysicians, psychologists, physiologists, naturalists, physicians, veterinarians, philosophers so called of the most diverse views and feelings, naturally and necessarily approach such a subject actuated by the most conflicting motives and opinions, by prejudice the most unreasonable, by ignorance the most profound.

Now, I have studied the subject of mind in other animals as compared with that of man, for a series of years, simply as a physician-naturalist.

As a physician it has been the special business of my professional life to deal practically with the phenomena of abnormal mentalisation in man-a circumstance that has

naturally involved a careful study of his normal mentalisation, and of the whole range of phenomena exhibited by the nervous system in health and disease.

More than twenty years ago it fell to my lot to conduct a series of investigations in comparative pathology, the general object and result of which was to show that the lower animals. are subject to the same kinds of bodily disease as those which affect man. At that time I had in Edinburgh occasion to experiment, for instance, on the transmission of disease from man to the lower animals, and from them to him; on the artificial induction of human disorders in the lower animals; and on the comparative action of poisons on the human and animal systems. Latterly my studies in comparative pathology have been determined in the direction of psychopathology. I was led in the first place to enquire what relation madness in the lower animals bears to insanity in man, the result being the conviction that the lower animals are subject to the same kinds of mental disorders, producible by the same causes, as in man. This enquiry formed but the precursor to a much more comprehensive investigation of the normal phenomena of mind throughout the animal kingdom.

My general conclusions, as regards both normal and disordered mind in the lower animals, were made public in a number of papers in certain London quarterly medical and other reviews and journals in 1871-72. These published papers having attracted the notice of the promoters of the International Scientific Series of volumes on current subjects of scientific interest, I was invited to contribute to that series a volume on 'Mind in the Lower Animals;' which invitation, though at first disposed to decline on account of the very limited professional leisure I could devote to a systematic exposition of my enquiries and their results, with the unfavourable nature for book-making of my daily avocations and of my provincial (country) residence, I was finally, after much correspondence, induced to accept. I did not, however, feel disposed to come prominently before the public without a still further and more careful study of the whole subject of the animal, including the human, mind, healthy and diseased. In particular, feeling, with John Stuart Mill

that a precise knowledge of what is already known is now an indispensable requisite for carrying knowledge further,'' I set myself to the careful perusal-note-taking the while— of the chief types of books which have been published relating to the habits of animals-a task which, along with the arrangement of the resultant notanda, has occupied all my leisure for several years.

As a naturalist I have long been accustomed to the patient and minute observation of facts, and to scientific generalisation from facts. I have been trained to separate fact on the one hand from fiction, and from inference based upon observation, on the other. As regards the habits of animals, I have had the same opportunities that all persons possess in this country of observing mental phenomena in domestic animals-such as the dog, horse, cat, ox, fowl, and in cage birds or other house pets. But I have also had the opportunity-which only foreign travel affords of observing, if not studying, the manners of domestic and wild animals in many distant and different parts of the world-including parts of Europe between Iceland in the north, and Spain and Italy in the south; of Africa, including especially Morocco and Egypt; of Asia (to wit, Syria); of America, including part of the United States and the Canadas; of Australasia, including New Zealand and New South Wales. The animals observed included, for instance, the buffalo and the camel, in addition to those above mentioned. I have, moreover, visited-sometimes repeatedly the principal zoological gardens, or menageries, in the world-such as those of London, Paris (including the Jardin des Plantes and the Jardin d'Acclimatation prior to the siege of Paris by the Prussians in 1870-71), Berlin, Dresden, New York, Dublin, Sydney, New South Wales, and that which formerly existed in Edinburgh-and have thus seen in the captive state large numbers of wild animals, representing the feræ naturæ of all quarters of the globe.

Regarding the whole subject of mind in animals

1 In a posthumous letter published in the Athenæum' of November 1873, p. 563.

from a medical and natural history point of view, I have studied it from first to last without any preconceived ideas -with no theory to defend, support, or illustrate-and ready throughout, without effort or regret, to renounce any belief which fact or truth might show to be scientifically untenable.

In the course of my enquiries I have amassed far too large a body of notes to condense into a single volume. These notes consist of (1) excerpts from my readings in books, whose nature and names will be found specified in the Bibliography; (2) reflections or criticisms on the statements made by the authorities consulted; (3) correspondence resulting from the publication by authors of doubtfully correct records of facts, or from the confusion of fact and fiction in narrative; (4) my own observations; and (5) reports taken down by me on the spot, or immediately after hearing them, of oral descriptions given by eye-witnesses of incidents illustrative of animal sagacity. In the present volumes-popular as they are in their aim and limited in their size-all that I attempt is to outline the subject of Mind in the Lower Animals, to illustrate their possession of the higher mental faculties as they occur in man, of reason as contradistinguished from mere instinct.

The work is to be regarded simply as what the French call a mémoire pour servir.' It is but a contribution and introduction to the subject of which it treats, and aims only at indicating to the student (1) the spirit and direction in which the said subject ought to be investigated; (2) the claims it has on man's attention; (3) the desirability of an exact separation of what we do from what we do not already know that first condition of all true knowledge; (4) the new significance of certain facts as interpreted by the light of modern science; and (5) that facts which controvert current popular fallacies or errors are nevertheless facts. The present work offers a certain rough classification of the facts of observation as already recorded, so as, it is hoped, to bring out their relative importance or significance; which classification may assist the reader still further to pursue the study of the subject by pointing out on the one

hand the kind of information already acquired, and on the other that which is still desirable or desiderated.

Designed originally to form a single volume of the International Scientific Series, I have found it impossible, after fruitless efforts at condensation, to compress what must be said in such a preliminary treatise within the compass of one volume of 300 or 400 pages. With the concurrence, therefore, on the one hand of the publishers, and on the other of the committee of the International Scientific Series of books, instead of issuing an incomplete work by the omission of what I regard as its most important halfthat which treats of mental disease-I have been constrained to cast the whole materials in two volumes, treating respectively of the varied phases or phenomena on the one hand of healthy, and on the other of diseased, mind.

6

Anxious as far as possible, in a work intended for popular use, to divest the subject of mind in animals of all unnecessary, repulsive, or confusing technicalities, I have purposely used the term mind itself, and all terms relating to its constituents or operations, in their ordinary, popular, or comprehensive sense. All men of experience and culture feel, rather than know, what these terms express or imply, though it has been abundantly shown, by the frequent unsuccessful attempts that have been made, how impossible it is to define them satisfactorily. Indeed, no two authors agree as to the signification that should be attached to such terms aswill,' 'feeling,' 'thought,' 'consciousness,' intention,' and so forth. So far as I can judge, after a special study of several of the fashionable modern systems of psychologyof mental or moral philosophy-such as those of Herbert Spencer and Professor Bain, I do not think anything would be gained by attempting, in such a work as the present, the strict definition of these or similar terms, or their restricted use, solely in a metaphysical, psychological, or other purely scientific or technical sense. I do not, therefore, here attempt psychological definition or classification, preferring to permit each reader to define and classify according to his own favourite system of nomenclature and arrangement.

I do not venture to generalise beyond a certain safe limit;