CHAPTER I. ON NATURAL LAWS. IN natural science, three suojects of inquiry may be distinguished: 1st, What exists? 2dly, What is the purpose or design of what exists? and, 3dly, Why was what exists designed for such uses as it evidently subserves? It is matter of fact, for instance, that arctic regions and the torrid zone exist,—that a certain kind of moss is abundant in Lapland in winter,-that the rein-deer feeds on it, and enjoys health and vigor in situations where most other animals would die; that cameis exist in Africa,-that they have broad hoofs, and stomachs fitted to retain water for a considerable time, - and that they flourish amid arid tracts of sand, where the rein-deer would hardly live for a day. All this falls under the inquiry, What exists? In contemplating these facts, the understanding is naturally led to infer that one object of the Lapland moss is to feed the rein-deer, and that one purpose of the deer is to assist man; and that broad feet have been given to the camel to allow it to walk on sand, and a retentive stomach to fit it for arid places in which water is found only at wide intervals. These conclusions result from inquiries into the uses or purposes of what exists; and such inquiries constitute a legitimate exercise of the human intellect. But 3dly, we may ask, Why were the physical elements of nature created such as they are? Why were summer, autumn, spring, and winter introduced? Why were animals formed of organized matter? Why were trackless wastes of snow and burning sand called into existence? These are inquiries why what exists was made such as it is, or into the will of the Deity in creation. Now, man's perceptive faculties are adequate to the first inquiry, and his reflective faculties to the second; but it may well be doubted whether he has powers suited to the third. My investigations are confined to the first and second, and I do not discuss the third. It cannot be too much insisted on, that the Creator has bestowed definite constitutions on physical nature and on man and animals, and that they are regulated by fixed laws. A law, in the common acceptation, denotes a rule of action; it implies a subject which acts, and that the actions or phenomena which that subject exhibits take place in an established and regular manner; and this is the sense in which I shall use it, when treating of physical substances and beings. Water, for instance, when at he level of the sea, an combined with that portion of heat indicated by 32° of Fahrenheit s thermomete, freezes or becomes solid; when combined with the rtion denoted by 212° of that instrument, it rises into vapor or steam. Here water and heat are the substances, and the freezing and rising in vapor are the appearances or phenomena presented by them; and when we say that these take place according to a law of Nature, we mean only that these modes of action appear, to our intellects, to be established in the very constitution of the water and heat, and in their natural relationship to each other; and that the processes of freezing and rising in vapor are constant appearances, when they are combined in these proportions, other conditions being the same. The ideas chiefly to be kept in view are, 1st, That all substances and beings have received a definite natural constitution; 2dly, That every mode of action, which is said to take place according to a natural law, is inherent in the constitution of the substance or being; and, 3dly, That the mode of action described is universal and invariable, whereever and whenever the substances or beings are found in the same condition. For example, water, at the level of the sea, freezes and boils at the same temperature, in China, in France, in Peru, and in England; and there is no exception to the regularity w which it exhibits these appear ances, when all its other conditions are the same. This last qualification, however, must constantly be attended to in all departments of science. If water be carried to the top of a mountain 20,000 feet high, it will boil at a lower temperature than 212°; but this depends on its relationship to the air, and takes place also according to fixed and invariable principles. The air exerts a great pressure on water. At the level of the sea the pressure is every where nearly the same, and in that situation the freezing and boiling points correspond all over the world; but on the top of a high mountain the pressure is much less, and the vapor, not being held down by so great a power of resistance, rises at a lower temperature than 212°. But this change of appearances does not indicate a change in the constitution of the water and the heat, but only a variation in the circumstances in which they are placed; and hence it is not correct to say, that water boiling on the tops of high mountains, at a lower temperature than 212°, is an exception to the general law of Nature. There are no exceptions to the laws of Nature; for the Creator is too wise and too powerful to make imperfect or inconsistent arrangements. The error is in the ⚫human mind inferring the law to be, that water boils at 212° in every altitude; when the real law is only that it boils at that temperature, at the level of the sea, in all countries,and that it boils at a lower temperature the higher it is carried, because then the pressure of the atmosphere is less. Intelligent beings are capable of observing nature and of modifying their actions. By means of their faculties, the laws impressed by the Creator on physical substances become known to them; and, when perceived, constitute laws to them, by which to regulate their conduct. For example, it is a physical law, that boiling water destroys the muscular and nervous systems of man. This is the result purely of the constitution of the body, and the relation between it and heat; and man cannot alter or suspend the law. But whenever the relation, and the consequences of disregarding it, are perceived, the mind is prompted to avoid infringe ment, in order to shun the torture attached by the Creator to the decomposition of the human body by heat. Similar views have long been taught by philosophers and divines. Bishop BUTLER, in particular, says:-' An Author of Nature being supposed, it is not so much a deduction of reason as a matter of experience, that we are thus under his government: under his government in the same sense as we are under the government of civil magistrates Because the annexing pleasure to some actions, and pain to others, in our power to do or forbear, and giving notice of this appointment beforehand to those whom it concerns, is the proper formal notion of government. Whether the pleasure or pain which thus follows upon our behavior, be owing to the Author of Nature's acting upon us every moment which we feel it, or to his having at once contrived and executed his own part in the plan of the world, makes no alteration as to the matter before us. For, if civil magistrates could make the sanctions of their laws take place, without interposing at all after they had passed them, without a trial and the formalities of an execution; if they were able to make their laws execute themselves, or every offender to execute them upon himself, we should be just in the same sense under their government then as we are now; but in a much higher degree and more perfect manner. Vain is the ridicule with which one foresees some persons will divert themselves, upon finding lesser pains considered as instances of Divine punishment. There is no possibility of answering or evading the general thing here intended, without denying all final causes. For, final causes being admitted, the pleasures and pains now mentioned must be admitted too, as instances of them. if they are, if God annexes delight to some actions and uneasiness to others, with an apparent design to induce us to act so and so, then he not only dispenses happiness and misery, but also rewards and punishes actions. If, for example, the pain which we feel upon doing what tends to the destruction of our bodies, suppose upon too near ap And proaches to fire, or upon wounding ourselves, be appointed by the Author of Nature to prevent our doing what thus tends to our destruction; this is altogether as much an instance of his punishing our actions, and consequently of our being under his government, as declaring, by a voice from heaven, that if we acted so He would inflict such pain upon us, and inflicting it whether it be greater or less.'* If, then, the reader keep in view that God is the Creator; that Nature, in the general sense, means the world which He has made,—and, in a more limited sense, the particular constitution which He has bestowed on any special object, of which we may be treating,—and that a law of Nature means the established mode in which the actions and phenomena of any creature or object exhibit themselves, and the obligation thereby imposed on inteliigent beings to attend to it, he will be in no danger of misunderstanding my meaning. Every natural object has received a definite constitution, in virtue of which it acts in a particular way. There must, therefore, be as many natural laws, as there are distinct modes of action of substances and beings, viewed by themselves. But substances and beings stand in certain relations to each other, and modify each other's action, in an established and definite manner, according to that relationship; altitude, for instance, modifies the effect of heat upon water. There must, therefore, be also as many laws of Nature, as there are relations between different substances and beings. It is impossible, in the present state of knowledge, to elucidate all these laws: numberless years may elapse before they shall be discovered; but we may investigate some of the most familiar and striking of them. Those that most readily present themselves bear reference to the great classes into which the objects around us may be divided; namely, Physical, Organic, and Intelligent. I shall there * BUTLER'S Works, vol. i. p. 44. The remarks of other authors on the Laws of Nature will be found in the Appendix No. I. p. 395. |