political sense it means a command, as when it is enjoined that men shall abstain from a certain act, such as theft or falsehood, or perform a certain duty, such as paying a tax. In this sense a law may be obeyed or disobeyed, and rewards and punishments may be awarded accordingly. In the scientific sense, however, a law means an invariable sequence or co-existence, as, for example, the law that bodies, when once set in motion, tend to move in a straight line, and with uniform velocity, for ever; that the three angles of any triangle are equal to two right angles; or that health depends on the proper discharge of the bodily functions. It is with laws of this kind alone that science is concerned, while laws, in the sense of commands or rules, belong to the province of art. A science consists of a body of invariable sequences or co-existences; an art of a body of precepts or rules for practice. Science treats of what is, was, or will be, and the ultimate principle by which its laws or uniformities are justified is the law of universal causation; art treats of what shall be, or ought to be, and the ultimate principle which forms the justification of its laws or rules, is, as Mr. Jeremy Bentham so clearly and forcibly pointed out, the principle of utility, or of the greatest happiness of mankind. The scientific laws are not commands, but invariable truths, which are never defeated (though they may be counteracted by other laws), and therefore they cannot, strictly speaking, be said to be obeyed or disobeyed, or to be broken or violated. However, phrases of this kind are constantly used, as when, for example, it is said that disease or poverty results from a violation of the sanitary or economical laws; the latter being here regarded as commands, and not as uniformities of cause and effect, which they really are. Such phrases may be used without inconvenience, if it be understood that they are merely metaphorical, and if the real meaning of a scientific law be clearly perceived. Too often, however, the ambiguity in the word causes much false reasoning, especially on social questions, and leads people to confound the fundamental distinction between science and art, and to speak of social science or its branches, as if they were a collection of general maxims and precepts, instead of a body of invariable sequences or co-existences.

The laws or uniformities of nature, with which science is concerned, are either ultimate or derivative: that is, they are either properties of the elementary substances which compose the universe, or consequences arising from them. There are some bodies in nature, to which the name of Permanent Causes, or primeval natural agents, has been given, as they have existed and produced their proper effects, throughout the whole of human experience and for an indefinite time previously. Such are the sun, the earth and planets, the elementary chemical substances, and some of their combinations, as air, water, &c. Of the origin of these bodies we are utterly ignorant nor can we perceive any regularity or law in their relative amount or position in space.

"All phenomena without exception which begin to exist," says Mr. Mill, that is, all except the primeval causes, are effects either imme

diate or remote of those primitive facts, or of some combination of them. There is no Thing produced, no event happening in the known universe, which is not connected by an uniformity, or invariable sequence, with some one or more of the phenomena which preceded it insomuch that it will happen again so often as those phenomena occur again, and as no other phenomenon having the character of a counteracting cause shall co-exist. These antecedent phenomena again, were connected in a similar manner with some that preceded them and so on, until we reach, as the ultimate step attainable by us, either the properties of some one primeval cause, or the conjunction of several. The whole of the phenomena of nature were therefore the necessary, or in other words, the unconditional, conse. quences of some former collocation of the Permanent Causes.'

The human body, and each of its different organs, digestive, locomotive, or reproductive, are governed by laws, just as definite and invariable as those of inanimate substances. To discover the laws of the body in a state of health is the province of physiology: while pathology investigates the laws of disease. The mind, also, forms no exception to the universal rule. Each of its three constituent states, namely, Thought, Feeling or Emotion, and Will, has its own fixed laws: the trains of ideas and sensations succeed each other according to definite principles of association, which are never departed from: and to ascertain these, forms the important aim of the science of psychology. Political economy, again, treats of the laws of the production and distribution of wealth; while social science, or, as it is often called, sociology (of which political economy is a branch), investigates the laws which determine the co-existence and succession of all the social phenomena. It examines the natural causes on which not only the wealth, but the political, moral, and sanitary condition of a people depend: the influences which determine the character, habits, social position, &c., of the various classes, and of the na tion as a whole.

It is of the utmost consequence that all should have a clear idea of causation, and a due reverence for the laws of nature. There are three things which chiefly unsettle men's minds on these most important points. The first is, the belief in supernatural interference: the idea that the invariability of nature's sequences is liable to be interrupted by supernatural causes, of whose laws we can have no knowledge. The error and danger of this belief have been so fully pointed out by numerous writers, and so ably opposed, at the expense of social penalties and indignities, by many heroic and devoted men, that I need not further dwell upon them.

The second unsettling belief is, that there is one phenomenon in nature, namely, the human will, which is not subject to the law of causation, but has what is called a self-determining power. This idea, which generally accompanies the preceding, is most paralysing to the science of mind, and has greatly retarded its progress. But the will, like all other parts of nature, depends on definite causes which it invariably follows. All our actions are determined by

motives; and this is practically recognised in our ordinary views of human conduct, however we may lose sight of it in theory. In judging of the actions of others, we always inquire what motives have led to them: what there is in the individual's character and circumstances that would naturally account for them: nor do we ever imagine that actions arise of themselves without any determining

causes.

These two beliefs form the chief artificial obstacles to a recognition of the order of the universe. But the real obstacle is one which does not arise from our theories, but from the great complexity of the natural phenomena themselves. The difficulty in ascertaining the laws of nature mainly depends on the mode in which different causes counteract each other, and commingle their effects: thus making the line of causation very difficult to unravel. The same effect also is often producible by many different causes. It is by these circumstances, called respectively by Mr. Mill the composition of causes, the intermixture of effects, and the plurality of causes, that the progress of science is chiefly retarded: and it is from the mode in which different laws thus counteract each other, that the popular belief has arisen, that "there is no general rule without an exception." But the truth is, that there is never an exception to a law of nature. All apparent exceptions are merely cases where the effect is counteracted by some other law. Nay, in the ordinary case of the composition of causes, each cause, even although counteracted, still produces its full and characteristic effect. For instance, if a body be held in the hand, the law by which it tends to fall to the ground is counteracted: but it still produces its full effect, as we feel by the sensation of weight. The exception to the ordinary rule of the composition of causes-that causes produce their full and characteristic effect even when counteracted-is in the case of chemical combinations, where two bodies by uniting produce an effect of a thoroughly different nature; but even this is rather an apparent than a real exception.

In consequence of their liability to be counteracted, laws of causation are stated as tendencies, when scientific precision is aimed at. For instance, the law is, that bodies tend to fall to the ground, not that they always do so: for the tendency may be counteracted. Mistakes are constantly made, and a distrust in the principles of science often engendered by not attending to the fact that all laws of causation are subject to counteraction. This is especially the case in complex sciences, such as physiology or political economy, where so many con flicting causes are always at work. But the laws of these sciences are not one whit less invariable than those of astronomy. When once clearly ascertained by a sufficient induction, they too must be regarded as admitting of no exception, and definitely settled for ever.

With these preliminary remarks on the laws of nature in general, I proceed to consider the law which appears to me beyond all comparison the most important and terrible subject for the contemplation of mankind, namely, the law of population.

THE LAW OF POPULATION, OR MALTHUSIAN LAW.

The Law of Population—that is, the law which regulates the inerease of mankind-may be arrived at from the following four propositions: the two first of which are undeniable, and must be granted by every one as soon as they are clearly understood; while the two last need proof.

PROPOSITION I.-Wherever in any country the actual increase of population is less than the possible increase, it is and can only be by some one or more of the six following causes or checks, viz., Celibacy, Prostitution, Sterility, Preventive Intercourse, Premature Death, and Emigration: whose collective amount varies inversely in proportion to the rapidity with which the population of the country is increasing, while the amount of each individually varies inversely in proportion to the others.

PROPOSITION II.-As a matter of fact, it is known that the population of different countries increases with very different degrees of rapidity. Thus the celebrated French statist, M. Moreau de Jonnès, has calculated, from the recent rate of their increase, the time which each of the undermentioned countries would take to double its population.

25

...

United States (deducting the contingents
furnished by immigration)

From this we see that the rate of increase in the United States (a new colony) is very much greater than in any country of the old world; and that among the latter countries some, especially England and Russia, increase much more rapidly than others. Whatever, then, be the difference between the rates of increase in these countries, it is owing absolutely and entirely to some one or more of the six checks given above: whose collective amount varies inversely in proportion to the rapidity with which the population of each country is increasing or has increased, while the amount of each individually varies inversely in proportion to the others.

PROPOSITION III.-From a consideration of the Law of Agricultural Industry, and an estimate of the rate at which the means of subsistence could be increased in old countries, even under the most favourable circumstances, it may be inferred with certainty, that these

means of subsistence could not possibly be increased so fast as to permit population to increase at its natural rate. Therefore the popu lation of old countries must always continue to be, as it always has been, powerfully checked by some one or more of the six checks given above; whose collective amount will vary inversely in proportion to the rapidity with which the population of each country may increase, while the amount of each individually will vary inversely in proportion to the others.

PROPOSITION IV.-Emigration is to be regarded, not as one of the permanent checks, to which man's choice is inexorably confined, but merely as a slight, temporary, and accidental palliative of the others. This is true even with regard to one old country alone, much more with regard to the whole world. The main causes which have retarded human increase, and some one or more of which have always acted, and will always continue to act, with enormous power in old countries, and in new colonies also as soon as their cultivation has increased to a certain extent, are the remaining five checks, namely, Celibacy, Prostitution, Sterility, Preventive Intercourse, and Premature Death; whose collective amount varies inversely in proportion to the rapidity with which the population of each country is increasing, and to the number of emigrants minus that of immigrants, while the amount of each individually varies inversely in proportion to the others.

I may here observe, that by the terms "possible or "natural" ncrease in the above propositions, I mean the increase which would take place, if all the children were born which the reproductive powers admit of, and if every individual lived to the full term of life. By the term "celibacy" is meant sexual abstinence, whether practised by married or unmarried people; and by "sterility" is meant all cases of barrenness, not arising from prostitution. The population table in the second proposition, is quoted from the work of Mr. Rickards (late Professor of Political Economy at Oxford), on Population and Capital, and I would remark that although it may be found to differ more or less from other tables drawn up at different periods (since the population of a country often increases faster at one time than at another, owing to the progress of the industrial arts, and other causes), still the same main facts will be found in all correct tables, namely, that population always increases much more rapidly in new colonies than in old countries, and that, among the latter, it increases much faster in some than in others.

According to the last Census returns, the population of Great Britain, and still more that of France, is increasing more slowly than the rate given by M. de Jonnès; indeed the French population has of late years been almost entirely stationary.

It is

The first of the four foregoing propositions is undeniable. merely an enumeration of all the modes in which the increase of the human race can be checked. These are obviously all reducible to the heads given above: or, in other words, to sexual abstinence, voluntary or involuntary unfruitful intercourse, premature death, and emigra