We may here observe, that all the arts whose operations are liable to be disturbed by meteorological influences are infected with the uncertainty which surrounds all the prognostications of meteorology. Thus, the art of navigation is disturbed by unforeseen storms and winds; the art of agriculture, by unexpected and inopportune extremes of heat and cold, drought and moisture. The works of the engineer are liable to be undermined or destroyed by unusual storms, inundations, currents of water, &c. Even medical treatment is often deranged by casual changes of temperature; and there appear to be atmospheric influences, inappreciable by our senses and artificial instruments, which generate epidemic diseases in men and animals, and also in vegetables.

On the other hand, those meteorological changes which are closely connected with constant astronomical periods, such as the succession of the seasons, are sometimes accompanied with corresponding phenomena, which in consequence obtain a cyclical character. Hence the periodical recurrence of the growth of the leaf, and the renewal of vegetable activity in the spring; followed by the death of the leaf, and the torpor of vegetable life at the approach of winter. Hence, likewise, the reproduction of birds, reptiles, insects, &c., at stated periods of the solar year.(17)

and watches being then unknown. The phenomena which measure these times are, he says, constant: but heavy rains, floods, severe cold, snow, fogs and mists, and other similar phenomena, which greatly disturb military operations, cannot, he adds, be foreseen.-ix. 16.

(17) Thales is said to have predicted an eclipse of the sun, which was visible in Asia Minor, within the limits of a year (see Herod, i. 74, with the commentators, and the passages cited by Menage ad Diog. Laert. i. 23). But as Thales is reported to have predicted in winter the abundance of the olive crop for the following autumn, and to have made a large sum of money by speculating on his foreknowledge (Aristot. Pol. i. 11); and as Anaxagoras is also said to have predicted the fall of an aërolithe (Plut. Lysand. 12; Plin. H. N. ii. 59), neither of which predictions is within the reach even of modern science-the probability is, that the prediction of a solar eclipse attributed to Thales is fabulous.

Helicon, of Cyzicus, a friend of Plato, is said to have predicted an eclipse of the sun (Plut. Dion. 19), and Dion an eclipse of the moon (ib. 24). C. Sulpicius Gallus, a Roman military tribune, predicted an eclipse of the moon in the year 160 B.C. In his address to the soldiers

§ 8 We have now obtained a general idea of the extent to which the methods furnished by the several physical sciences afford the means of predicting the future, and of the differences between the powers of prediction which they respectively possess. We have seen that while astronomy can foretel with certainty the motions of the solar system, the prophetic powers of meteorology are feeble and limited, and consist principally in assigning certain limits to the possible variations of weather. We have likewise seen that, although the laws of motion, sound, and light, and of the chemical relations of bodies, are laid down in general propositions independent of time, and therefore as applicable to the future as to the past, yet these propositions merely express the tendencies of causes operating freely; and therefore, when we are unable in practice to exclude all disturbing causes, we are unable to anticipate the future with certainty. It has also appeared, that a similar distinction applies to the physical nature of man. The functions of the human body are described by the physiologist in general terms, which are as true of the future as of the past; but no medical skill can predict with accuracy the duration of life in any individual person, nor can a physician always anticipate truly the course of a disease, or the influence of his treatment upon a patient.

Science, indeed, or theory, in itself (as we have seen), is incapable of prediction. It merely co-ordinates phenomena, and lays down general laws of sequence. By the help of the laws of causation thus determined, the practitioner is able to predict the future in individual cases; and the instruments of anticipation which theory places in his hand vary in their potency, according to the nature of the subject.

Our object in making this review was, to compare the prophetic powers of the physical sciences with those of the sciences relating to man as a rational being. We therefore now proceed

before the eclipse, he is reported to have said: Id quia naturali ordine statis temporibus fiat, et sciri ante et prædici posse.'-Livy, xliv. 37. Some learned men, in the large towns of the East, can predict an eclipse of the sun or moon.-Niebuhr, Description de l'Arabie, p. 105.

to a similar examination of the latter class; and we will offer a few remarks, in reference to this point, upon the sciences of metaphysics, logic, philosophy, esthetics, and ethics, before we arrive at the science of politics, the proper subject of our inquiry.

§ 9 Metaphysical science describes the perceptive and intellectual operations of the human mind. It teaches by what means, and through what channels, our knowledge is acquired; how we represent our thoughts by language; and in what the processes of sensation, abstraction, memory, imagination, &c., consist. The researches of metaphysics aim at nothing historical, nor do they relate to anything recurrent in its nature. When, therefore, any metaphysical truth has been established, it applies as much to the future as to the past. If the origin of our visual judgments respecting distance has been correctly explained, the explanation will continue to hold good of all future time, as long as human nature remains unchanged. All propositions respecting the perceptions of our senses, the signification of general terms, and the like, are just as applicable to the future as propositions respecting the circulation of the blood, or the functions of the brain. The uncertainty of metaphysics, like the uncertainty of physiology, applies as much to the past as to the future. It is in many cases difficult to determine the operations of our minds, as it is likewise difficult to determine the vital operations of our bodily organs. But when either the one or the other has been determined, a law of our nature, mental or bodily, has been ascertained, which is as true of the future as of the past. It is not a part of the present inquiry to estimate the comparative uncertainty of physiology and metaphysics, but we may remark that, although our mental operations are invisible and intangible, they are nevertheless the subjects of consciousness, whereas our bodily functions (such, for example, as digestion, secretion, circulation, &c.) are not in general the subjects of consciousness, and are not, during life, accessible to the observation of the senses.

§ 10 The business of logic is to analyze the mental processes which are concerned in reasoning, and to found upon

this analysis precepts for the guidance of the mind in argumentative inquiries and in investigations after truth, speculative and practical. In either of its two capacities, either as describing the processes by which ratiocination is conducted, or as furnishing a practical method for the reasoner, its results are independent of time, and have no special application to the past. As a scientific analysis of our mental processes, its truths are universal—as a practical art and method, its rules are necessarily prospective, and, though founded on experience, are intended to direct the mind of the student with respect to its future movements.

Connected in some degree with logic is philology, or the science of language. Philology is principally a historical department of knowledge. It traces the origin of languages, their affinities, and their successive changes under the operation of different causes. It also lays down those empirical laws which govern the correspondence of vowel and consonant sounds, or of grammatical forms, in cognate languages, as in Sanscrit, Greek, Latin, and Gothic-in the Romance languages, or in the High and Low German. It establishes the principles by which grammar expounds the forms and syntax, and lexicography expounds the etymology and signification of words. It likewise investigates the doctrine of hermeneutics, and shows how the writings of former times are to be interpreted. From this enumeration it will be seen that philology, so far as it is descriptive and historical, has no concern with the future, and does not profess to predict. Each language is a system of conventional sounds, framed by an intelligent process, and concentrating the results of much observation and reflection. Philology undertakes to exhibit the empirical laws which have presided over the formation of this language, but it cannot fix the laws for its ulterior changes, nor can it do more than form a probable conjecture as to the course of those future changes. The rules of grammar merely express the formal and syntactical relations of words, according to the correct usage; and the dictionary assigns their significations according to the same standard. The gram

mar and dictionary, therefore, of each language merely collect the actual results of a certain usage; but they do not lay down permanent laws of human nature, or express universal truths.

§ 11 It is only in its function of interpreter of the records of the past that philology aspires to the establishment of principles admitting of a universal application. In this department, it borders upon the province of literary criticism, and of esthetics, or the science of taste. Esthetical science investigates the causes of beauty in nature and art. It considers the principles of painting and sculpture-also of architecture, gardening, dress, &c., so far as they are decorative arts, and do not involve merely mechanical considerations. It likewise sits in judgment upon poetry, and other works of imagination. Esthetical criticism is, to a certain extent, historical, and confined to particular compositions; but its maxims are mainly founded on general principles of human nature, and are not empirical. Hence, when sound canons of taste in painting, sculpture, poetry, or other department of the fine arts, have been established, they are permanent in their application. A good model of style, either in the arts of design or in literature, remains a subject of imitation, though liable to the alternations and caprices of fashion.

§ 12 Our esthetical are closely connected with our ethical feelings, as may be observed in theatrical representations. The judgment of the audience upon a drama, considered as a work of art, is materially influenced by the extent to which their emotions have been affected. We pass, therefore, naturally to the consideration of ethics, together with those other departments of social science which are not included in politics.

Ethics, in the first place, may be limited to mere description— to a generalization of the results derived from an observation of men's moral actions. Such, for example, is a description of the moral sentiments-as anger, pity, fear, grief, indignation, and the like. There are certain emotions which are common to the whole human race, and which a similarity of circumstances tends to excite in every breast, although, in some cases, they may be repressed by a sense of duty, or other counteracting