Such is the constant, the invariable course, of Nature; such is the eternal circle of mutation, which all that exists is obliged to describe. It is thus motion generates, preserves for a time, and successively, destroys, one part of the universe by the other; whilst the sum of existence remains eternally the same. Nature, by its combinations, produces suns, which place themselves in the centre of so many systems: she forms planets, which, by their peculiar essence, gravitate and describe their revolutions round these suns: by degrees the motion is changed altogether, and becomes eccentric: perhaps the day may arrive when these wondrous masses will disperse, of which man, in the short space of his existence, can only have a faint and transient glimpse.
It is clear, then, that the continual motion inherent in matter, changes and destroys all beings; every instant depriving them of some of their properties, to substitute others: it is motion, which, in thus changing their actual essence, changes also their order, their direction, their tendency, and the laws which regulate their mode of acting and being: from the stone formed in the bowels of the earth, by the intimate combination and close coherence of similar and analogous particles, to the sun, that vast reservoir of igneous particles, which sheds torrents of light over the firmament; from the benumbed oyster, to the thoughtful and active man; we see an uninterrupted progression, a perpetual chain of motion and combination; from which is produced, beings that only differ from each other by the variety of their elementary matter—by the numerous combinations of these elements, from whence springs modes of action and existence, diversified to infinity. In generation, in nutrition, in preservation, we see nothing more than matter, variously combined, of which each has its peculiar motion, regulated by fixed and determinate laws, which oblige them to submit to necessary changes. We shall find, in the formation, in the growth, in the instantaneous life, of animals, vegetables, and minerals, nothing but matter; which combining, accumulating, aggregating, and expanding by degrees, forms beings, who are either feeling, living, vegetating, or else destitute of these faculties; which, having existed some time under one particular form, are obliged to contribute by their ruin to the production of other forms.
Thus, to speak strictly, nothing in Nature is either born, or dies, according to the common acceptation of those terms. This truth was felt by many of the ancient philosophers. PLATO says, that according to tradition, "the living were born of the dead, the same as the dead did come of the living; and that this is the constant routine of Nature." He adds from himself, "who knows, if to live, be not to die; and if to die, be not to live?" This was the doctrine of PYTHAGORAS, a man of great talent and no less note. EMPEDOCLES asserts, "there is neither birth nor death, for any mortal; but only a combination, and a separation of that which was combined, and that this is what amongst men they call birth, and death." Again he remarks, "those are infants, or short-sighted persons, with very contracted understandings, who imagine any thing is born, which did not exist before, or that any thing can die or perish totally."
CHAP. IV.
Laws of Motion, common to every Being of Nature.—Attraction and Repulsion.—Inert Force.—Necessity.
Man is never surprised at those effects, of which he thinks he knows the cause; he believes he does know the cause, as soon as he sees them act in an uniform and determinate manner, or when the motion excited is simple: the descent of a stone, that falls by its own peculiar weight, is an object of contemplation to the philosopher only; to whom the mode by which the most immediate causes act, and the most simple motion, are no less impenetrable mysteries than the most complex motion, and the manner by which the most complicated causes give impulse. The uninformed are seldom tempted either to examine the effects which are familiar to them, or to recur to first principles. They think they see nothing in the descent of a stone, which ought to elicit their surprise, or become the object of their research: it requires a NEWTON to feel that the descent of heavy bodies is a phenomenon, worthy his whole, his most serious attention; it requires the sagacity of a profound experimental philosopher, to discover the laws by which heavy bodies fall, by which they communicate to others their peculiar motion. In short, the mind that is most practised in philosophical observation, has frequently the chagrin to find, that the most simple and most common effects escape all his researches, and remain inexplicable to him.
When any extraordinary, any unusual, effect is produced, to which our eyes have not been accustomed; or when we are ignorant of the energies of the cause, the action of which so forcibly strikes our senses, we are tempted to meditate upon it, and take it into our consideration. The European, accustomed to the use of GUNPOWDER, passes it by, without thinking much of its extraordinary energies; the workman, who labours to manufacture it, finds nothing marvellous in its properties, because he daily handles the matter that forms its composition. The American, to whom this powder was a stranger, who had never beheld its operation, looked upon it as a divine power, and its energies as supernatural. The uninformed, who are ignorant of the true cause of THUNDER, contemplate it as the instrument of divine vengeance. The experimental philosopher considers it as the effect of the electric matter, which, nevertheless, is itself a cause which he is very far from perfectly understanding.—It required the keen, the penetrating mind of a FRANKLIN, to throw light on the nature of this subtle fluid—to develop the means by which its effects might be rendered harmless—to turn to useful purposes, a phenomenon that made the ignorant tremble—that filled their minds with terror, their hearts with dismay, as indicating the anger of the gods: impressed with this idea, they prostrated themselves, they sacrificed to JUPITER, to deprecate his wrath.
Be this as it may, whenever we see a cause act, we look upon its effect as natural: when this cause becomes familiar to the sight, when we are accustomed to it, we think we understand it, and its effects surprise us no longer. Whenever any unusual effect is perceived, without our discovering the cause, the mind sets to work, becomes uneasy; this uneasiness increases in proportion to its extent: as soon as it is believed to threaten our preservation, we become completely agitated; we seek after the cause with an earnestness proportioned to our alarm; our perplexity augments in a ratio equivalent to the persuasion we are under: how essentially requisite it is, we should become acquainted with the cause that has affected us in so lively a manner. As it frequently happens that our senses can teach us nothing respecting this cause which so deeply interests us—which we seek with so much ardour, we have recourse to our imagination; this, disturbed with alarm, enervated by fear, becomes a suspicious, a fallacious guide: we create chimeras, fictitious causes, to whom we give the credit, to whom we ascribe the honour of those phenomena by which we have been so much alarmed. It is to this disposition of the human mind that must be attributed, as will be seen in the sequel, the religious errors of man, who, despairing of the capacity to trace the natural causes of those perplexing phenomena to which he was the witness, and sometimes the victim, created in his brain (heated with terror) imaginary causes, which have become to him a source of the most extravagant folly.