FIG. 94. Larynx of Camel laid open.. 95. Larynx of Horse....... 96. Lateral and Posterior View of Didelphis Opossum 204 205 206 215 217 98. Lateral View of Larynx of Chimpanzee... ...................... .............................. ON THE NATURE, CONNEXIONS, AND USES OF THE GREAT DEPARTMENTS OF HUMAN KNOWLEDGE. BEFORE man became a philosopher he was a discoverer; and in his capacity for discovery, and for reasoning on its results, he differs widely from all other beings. In the organic world there is no history but the history of man. The doings of one pair, or of one colony of inferior animals, however sagacious, are the doings of generation after generation. Birds build their nests in our gardens and shrubberies as they built their nests in Eden; the bees in our hives construct their honeycomb, as the bees of Samson's time did that which he took from the lion's carcase; and the beavers of Canada rear their dams, and huts, and burrows at this day as they have done ever since their species was created. How different is the account of man's proceedings from the time of his first appearance upon the earth! What variety in his modes of clothing himselfof building habitations of defending himself from beasts of preyof transporting himself from place to place-of subjecting to his power the animate and the inanimate Creation! In the first advances made by primitive man, his capacity for the attainment of knowledge shines forth almost as vividly as in the discoveries made during his most advanced state of civilization. To draw a distinction between the faculties of man and the faculties of the highest among the animal creation has always been a task of much difficulty; and yet how frivolous appear the attempts to trace a proximity between endowments but outwardly similar, the moment the actual fruits of man's faculties are contrasted with the nothingness of effect produced by any other species on the surface of the earth! It can hardly indeed be said with truth that man's mere 14 THE PROMINENT GROUPS OF HUMAN KNOWLEDGE. senses are more perfect than those of the animals which stand near him in the scale of being; but it is an obvious truth that he has a capacity to originate ideas which mould the observations of sense on a higher and more perfect type. In man's carly progress, the rudiments of almost every branch of knowledge may readily be traced. His intellectual pre-eminence in the animal kingdom may be reduced to a few prominent headsnamely, to his great capacity, in the first place, for appreciating the abstract relations of number and quantity; secondly, to his exact perception of the resemblances and the differences of objects of sense; thirdly, to his inherent disposition to form objects and appearances, which agree even in one quality or mode of presenting themselves, into groups—which are afterwards to be recognised as possessed of a unity of character; fourthly, to his complete feeling of the distinctness of his bodily self from the rest of nature; to his instant perception of its slightest change of position or attitude; and, to his almost unlimited voluntary power over its movements, so that it becomes an exact measure of the numerous relative properties of surrounding bodies; and, lastly, to his capacity for looking inwards upon himself, and taking note of the special effects produced on his internal nature by persons, and things, and circumstances. With these several heads the great departments of human knowledge, as we shall discover, intimately connect themselves. Science. The systems of knowledge founded on intuitive convictions of the human mind, to which the name of scienee is currently given, are, in particular, the Abstract or Mathematical Sciences. Those collected from the perceptions of sense, with or without the aid of instruments and of the abstract sciences, and methodised by man's faculty of grouping individual appearances into compound unities, are the Inductive Sciences, under which falls the chief part of physical knowledge - namely, several branches of Natural Philosophy, the whole of the Electrical Sciences, Chemistry, and some parts of Physiology. Those founded in the same manner upon the organic kingdoms of nature, with the aid of certain fundamental intuitive convictions of the human mind, constitute the Physiological sciences. Those directly deduced from man's contemplation of the subjects of his consciousness, and the report of others as to the results of their reflections on what consciousness has taught them, make up the Psychological sciences, Metaphysics, Ethics, &c. Those drawn from the contemplation of man in his social state, as bearing on the welfare of the community, are represented chiefly by Statistics and Political Economy. Those which rest on moral evidence, in its three degrees of possibility, probability, and moral certainty, rather than on the evidence of sense, are Government, Law, Medicine, Taste, Criticism, &c. Those which are formed by comparing the VALUE OF THE TERM SCIENCE. 15 substances composing the exterior of our planet, and the individuals of the animal and vegetable kingdoms, and by marking their resemblances and differences, constitute the Natural History of the three Kingdoms of Nature. And lastly, the systems of knowledge derived from the observation of the minute structure of minerals, plants, and animals, and the grouping of certain frequently recurring resemblances into separate unities, each denoted by a single expression, constitute what have been termed the Descriptive Sciences, such as Zootomy, or Anatomy commonly so called, Phytotomy or Vegetable Anatomy, and Crystallography. Such, then, is an enumeration of the great branches of human knowledge, of which it is our intention in the present undertaking to treat. But, at present, let us examine more narrowly the resemblances and differences of the evidence on which these several branches of knowledge depend, and endeavour to ascertain their connections and the precise uses to which each is subservient. We will premise, however, that although the name of science is currently applied to the more profound parts of man's studies, the term has no definite signification. In particular, it is employed indiscriminately to denote those systems of knowledge which are deduced from the inherent or intuitive convictions of the human mind, as well as those systems of knowledge which are built upon the perceptions of sense, variously grouped into a whole, because of the agreement of the members of each group in one mode of presenting themselves. But vague as is the term science, it is too firmly rooted to be rejected. Geometry. When any part of Mathematics, for example, Geometry, is compared with some one of the Inductive Sciences, such as Chemistry, it is discovered how loosely the term science must be used to apply equally to both. For this purpose, we select for contrast the properties of the alkalies, on the one hand, and on the other the remarkable property of the right-angled triangle, that the square of its hypotenuse is equivalent to the sum of the squares of the two sides. The alkalies—that is, the pure caustic alkalies are freely soluble in water and in alcohol; each saturates its own proportion of every known acid; and were a new acid discovered, it would only be necessary to ascertain how much of it is required to saturate a given quantity of one of the alkalies, to pronounce how much of each of the others that same quantity would saturate; the alkalies, besides, form soaps with oils; they change vegetable blue colours to green, and yellows to brown. By means of these properties, the chemist is able to detect the presence of any pure alkali in his analysis; and such is one of the great objects which the science of Chemistry has in view. But the point which we wish chiefly to be |