Baron D’Holbach

The System of Nature

Chapter 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.

In Nature, however, there can be only natural causes and effects; all motion excited in this Nature, follows constant and necessary laws: the natural operations, to the knowledge of which we are competent, of which we are in a capacity to judge, are of themselves sufficient to enable us to discover those which elude our sight; we can at least judge of them by analogy. If we study Nature with attention, the modes of action which she displays to our senses will teach us not to be disconcerted by those which she refuses to discover. Those causes which are the most remote from their effects, unquestionably act by intermediate causes; by the aid of these, we can frequently trace out the first. If in the chain of these causes we sometimes meet with obstacles that oppose themselves to our research, we ought to endeavour by patience and diligence to overcome them; when it so happens we cannot surmount the difficulties that occur, we still are never justified in concluding the chain to be broken, or that the cause which acts is super-natural. Let us, then, be content with an honest avowal, that Nature contains resources of which we are ignorant; but never let us substitute phantoms, fictions, or imaginary causes, senseless terms, for those causes which escape our research; because, by such means we only confirm ourselves in ignorance, impede our enquiries, and obstinately remain in error.

In spite of our ignorance with respect to the meanderings of Nature, (for of the essence of being, of their properties, their elements, their combinations, their proportions, we yet know the simple and general laws, according to which bodies move;) we see clearly, that some of these laws, common to all beings, never contradict themselves; although, on some occasions, they appear to vary, we are frequently competent to discover that the cause becoming complex, from combination with other causes, either impedes or prevents its mode of action being such as in its primitive state we had a right to expect. We know that active, igneous matter, applied to gunpowder, must necessarily cause it to explode: whenever this effect does not follow the combination of the igneous matter with the gunpowder—whenever our senses do not give us evidence of the fact, we are justified in concluding, either that the powder is damp, or that it is united with some other substance that counteracts its explosion. We know that all the actions of man have a tendency to render him happy: whenever, therefore, we see him labouring to injure or destroy himself, it is just to infer that he is moved by some cause opposed to his natural tendency; that he is deceived by some prejudice; that, for want of experience, he is blind to consequences: that he does not see whither his actions will lead him.

If the motion excited in beings was always simple; if their actions did not blend and combine with each other, it would be easy to know, and we should be assured, in the first instance, of the effect a cause would produce. I know that a stone, when descending, ought to describe a perpendicular: I also know, that if it encounters any other body which changes its course, it is obliged to take an oblique direction, but if its fall be interrupted by several contrary powers, which act upon it alternately, I am no longer competent to determine what line it will describe. It may be a parabola, an ellipsis, spiral, circular, &c. this will depend on the impulse, it receives, and the powers by which it is impelled.

The most complex motion, however, is never more than the result of simple motion combined: therefore as soon as we know the general laws of beings and their action, we have only to decompose, to analyse them, in order to discover those of which they are combined; experience teaches us the effects we are to expect. Thus it is clear, the simplest motion causes that necessary junction of different matter, of which all bodies are composed: that matter, varied in its essence, in its properties, in its combinations, has each its several modes of action or motion, peculiar to itself; the whole motion of a body is consequently the sum total of each particular motion that is combined.

Amongst the matter we behold, some is constantly disposed to unite, whilst other is incapable of union; that which is suitable to unite, forms combinations, more or less intimate, possessing more or less durability: that is to say, with more or less capacity to preserve their union, to resist dissolution. Those bodies which are called solids, receive into their composition a great number of homogeneous, similar, and analogous particles, disposed to unite themselves with energies conspiring or tending to the same point. The primitive beings, or elements of bodies, have need of supports, of props; that is to say, of the presence of each other, for the purpose of preserving themselves; of acquiring consistence or solidity: a truth, which applies with equal uniformity to what is called physical, as to what is termed moral.

It is upon this disposition in matter and bodies, with relation to each other, that is founded those modes of action which natural philosophers designate by the terms attraction, repulsion, sympathy, antipathy, affinities, relations; that moralists describe under the names of love, hatred, friendship, aversion. Man, like all the beings in nature, experiences the impulse of attraction and repulsion; the motion excited in him differing from that of other beings, only, because it is more concealed, and frequently so hidden, that neither the causes which excite it, nor their mode of action are known. This system of attraction and repulsion is very ancient, although it required a Newton to develop it. That love, to which the ancients attributed the unfolding, or disentanglement of chaos, appears to have been nothing more than a personification of the principle of attraction. All their allegories and fables upon chaos, evidently indicate nothing more than the accord or union that exists between analogous and homogeneous substances; from whence resulted the existence of the universe: whilst discord or repulsion, which they called sois, was the cause of dissolution, confusion, and disorder; there can scarcely remain a doubt, but this was the origin of the doctrines of the two principles. According to Diogenes Laërtius, the philosopher, Empedocles, asserted, that “there is a kind of affection by which the elements unite themselves; and a sort of discord, by which they separate or remove themselves.”

However it may be, it is sufficient for us to know that by an invariable law, certain bodies are disposed to unite with more or less facility; whilst others cannot combine or unite themselves: water combines itself readily with salt, but will not blend with oil. Some combinations are very strong, cohering with great force, as metals; others are extremely feeble, their cohesion slight and easily decomposed, as in fugitive colours. Some bodies, incapable of uniting by themselves, become susceptible of union by the agency of other bodies, which serve for common bonds or mediums. Thus, oil and water, naturally heterogeneous, combine and make soap, by the intervention of alkaline salt. From matter diversely combined, in proportions varied almost to infinity, result all physical and moral bodies; the properties and qualities of which are essentially different, with modes of action more or less complex: which are either understood with facility, or difficult of comprehension, according to the elements or matter that has entered into their composition, and the various modifications this matter has undergone.

It is thus, from the reciprocity of their attraction, the primitive imperceptible particles of matter, which constitute bodies, become perceptible, form compound substances, aggregate masses; by the union of similar and analogous matter, whose essences fit them to cohere. The same bodies are dissolved, their union broken, whenever they undergo the action of matter inimical to their junction. Thus by degrees are formed, plants, metals, animals, men; each grows, expands, and increases in its own system or order; sustaining itself in its respective existence, by the continual attraction of analogous matter; to which it becomes united, and by which it is preserved and strengthened. Thus, certain aliments become fit for the sustenance of man, whilst others destroy his existence: some are pleasant to him, strengthen his habit; others are repugnant to him, weaken his system: in short, never to separate physical from moral laws, it is thus that men, mutually attracted to each other by their reciprocal wants, form those unions which we designate by the terms, marriage, families, societies, friendships, connexions: it is thus that virtue strengthens and consolidates them; that vice relaxes or totally dissolves them.

Of whatever nature may be the combination of beings, their motion has always one direction or tendency: without direction we could not have any idea of motion: this direction is regulated by the properties of each being; as soon as they have any given properties, they necessarily act in obedience to them: that is to say, they follow the law invariably determined by these same properties; which, of themselves, constitute the being such as he is found, and settle his mode of action, which is always the consequence of his manner of existence. But what is the general direction, or common tendency, we see in all beings? What is the visible and known end of all their motion? It is to conserve their actual existence—to preserve themselves—to strengthen their several bodies—to attract that which is favorable to them—to repel that which is injurious them—to avoid that which can harm them—to resist impulsions contrary to their manner of existence, and to their natural tendency.

To exist, is to experience the motion peculiar to a determinate essence: to conserve this existence, is to give and receive that motion from which results its maintenance:—it is to attract matter suitable to corroborate its being—to avoid that by which it may be either endangered or enfeebled. Thus, all beings of which we have any knowledge, have a tendency to conserve themselves, each after its peculiar manner: the stone, by the firm adhesion of its particles, opposes resistance to its destruction. Organized beings conserve themselves by more complicated means, but which are, nevertheless, calculated to maintain their existence against that by which it may be injured. Man, both in his physical and in his moral capacity, is a living, feeling, thinking, active being; who, every instant of his duration, strives equally to avoid that which may be injurious, and to procure that which is pleasing to him, or that which is suitable to his mode of existence; all his actions tending solely to conserve himself. St. Augustine admits this tendency in all whether organized or not.

Conservation, then, is the common point to which all the energies, all the powers, all the faculties of beings, seem continually directed. Natural philosophers call this direction or tendency, self-gravitation: Newton calls it inert force: moralists denominate it in man, self-love which is nothing more than the tendency he has to preserve himself—a desire of happiness—a love of his own welfare—a wish for pleasure—a promptitude in seizing on every thing that appears favourable to his conservation—a marked aversion to all that either disturbs his happiness, or menaces his existence—primitive sentiments, that are common to all beings of the human species; which all their faculties are continually striving to satisfy; which all their passions, their wills, their actions, have eternally for their object and their end. This self-gravitation, then, is clearly a necessary disposition in man, and in all other beings; which, by a variety means, contribute to the preservation of the existence they have received, as long as nothing deranges the order of their machine, or its primitive tendency.

Cause always produces effect; there can be no effect without cause. Impulse is always followed by some motion, more or less sensible; by some change, more or less remarkable in the body which receives it. But motion, and its various modes of displaying itself, is, as has been already shewn, determined by the nature, the essence, the properties, the combinations of the beings acting. It must, then, be concluded that motion, or the modes by which beings act, arises from some cause; that as this cause is not able to move or act, but in conformity with the manner of its being or its essential properties, it must equally be concluded, that all the phenomena we perceive are necessary; that every being in Nature, under the circumstances in which it is placed, and with the given properties it possesses, cannot act otherwise than it does.

Necessity is the constant and infallible relation of causes with their effects. Fire consumes, of necessity, combustible matter plated within its circuit of action: man, by fatality, desires either that which really is, or appears to be serviceable to his welfare. Nature, in all the extraordinary appearances she exhibits, necessarily acts after her own peculiar essence: all the beings she contains, necessarily act each after its own a individual nature: it is by motion that the whole has relation with its parts; and these parts with the whole: it is thus that in the general system every thing is connected: it is itself but an immense chain of causes and effects, which flow without ceasing, one from the other. If we reflect, we shall be obliged to acknowledge that every thing we see is necessary; that it cannot be otherwise than it is; that all the beings we behold, as well as those which escape our sight, act by invariable laws. According to these laws, heavy bodies fall— light bodies ascend—analogous substances attract each other—beings tend to preserve themselves—man cherishes himself; loves that which he thinks advantageous—detests that which he has an idea may prove unfavourable to him.—In fine, we are obliged to admit, there can be no perfectly independent energy—no separated cause—no detached action, in a nature where all the beings are in a reciprocity of action—who, without interruption, mutually impel and resist each other—who is herself nothing more than an eternal circle of motion, given and received according to necessary laws; which under the same given incidents, invariably produce the same effect.

Two examples will serve to throw the principle here laid down, into light—one shall be taken from physics, the other from morals.

In a whirlwind of dust, raised by elemental force, confused as it appears to our eyes, in the most frightful tempest excited by contrary winds, when the waves roll high as mountains, there is not a single particle of dust, or drop of water, that has been placed by chance, that has not a cause for occupying the place where it is found; that does not, in the most rigorous sense of the word, act after the manner in which it ought to act; that is, according to its own peculiar essence, and that of the beings from whom it receives this communicated force. A geometrician exactly knew the different energies acting in each case, with the properties of the particles moved, could demonstrate that after the causes given, each particle acted precisely as it ought to act, and that it could not have acted otherwise than it did.

In those terrible convulsions that sometimes agitate political societies, shake their foundations, and frequently produce the overthrow of an empire; there is not a single action, a single word, a single thought, a single will, a single passion in the agents, whether they act as destroyers, or as victims, that is not the necessary result of the causes operating; that does not act, as, of necessity, it must act, from the peculiar essence of the beings who give the impulse, and that of the agents who receive it, according to the situation these agents fill in the moral whirlwind. This could be evidently proved by an understanding capacitated to rate all the action and re-action, of the minds and bodies of those who contributed to the revolution.

In fact, if all be connected in Nature, if all motion be produced, the one from the other, notwithstanding their secret communications frequently elude our sight; we ought to feel convinced of this truth, that there is no cause, however minute, however remote, that does not sometimes produce the greatest and most immediate effects on man. It may, perhaps, be in the parched plains of Lybia, that are amassed the first elements of a storm or tempest, which, borne by the winds, approach our climate, render our atmosphere dense, and thus operating on the temperament, may influence the passions of a man, whose circumstances shall have capacitated him to influence many others, who shall decide after his will the fate of many nations.

Man, in fact, finds himself in Nature, and makes a part of it: he acts according to laws, which are appropriate to him; he receives in a manner more or less distinct, the action and impulse of the beings who surround him; who themselves act after laws that are peculiar to their essence. Thus he is variously modified; but his actions are always the result of his own energy, and that of the beings who act upon him, and by whom he is modified. This is what gives such variety to his determinations—what generally produces such contradiction in his thoughts, his opinions, his will, his actions; in short, in that motion, whether concealed or visible, by which he is agitated. We shall have occasion, in the sequel, to place this truth, at present so much contested, in a clearer light: it will be sufficient for our purpose at present to prove, generally, that every thing in Nature is necessary—that nothing to be found in it can act otherwise than it does.

Motion, alternately communicated and received, establishes the connection or relation between the different orders of beings: when they are in the sphere of reciprocal action, attraction approximates them; repulsion dissolves and separates them; the one strengthens and preserves them; the other enfeebles and destroys them. Once combined, they have a tendency to conserve themselves in that mode of existence, by virtue of their inert force; in this they cannot succeed, because they are exposed to the continual influence of all other beings, who perpetually and successively act upon them; their change of form, their dissolution, is requisite to the preservation of Nature herself: this is the sole end we are able to assign her—to which we see her tend without intermission—which she follows without interruption, by the destruction and reproduction of all subordinate beings, who are obliged to submit to her laws—to concur, by their mode of action, to the maintenance of her active existence, so essentially requisite to the great whole.

It is thus each being is an individual, who, in the great family, performs his necessary portion of the general labour—who executes the unavoidable task assigned to him. All bodies act according to laws, inherent in their peculiar essence, without the capability to swerve, even for a single instant, from those according to which Nature herself acts. This is the central power, to which all other powers, essences, and energies, are submitted: she regulates the motions of beings, by the necessity of her own peculiar essence: she makes them concur by various modes to the general plan: this appears to be nothing more than the life, action, and maintenance of the whole, by the continual change of its parts. This object she obtains, in removing them, one by the other; by that which establishes, and by that which destroys, the relation subsisting between them; by that which gives them, and that which deprives them of, their forms, combinations, proportions, and qualities, according to which they act for a time, after a given mode; these are afterwards taken from them, to make them act after a different manner. It is thus that Nature makes them expand and change, grow and decline, augment and diminish, approximate and remove, forms and destroys them, according as she finds it requisite to maintain the whole; towards the conservation which this Nature is herself essentially necessitated to have a tendency.

This irresistible power, this universal necessity, this general energy, then, is only a consequence of the nature of things; by virtue of which every thing acts, without intermission, after constant and immutable laws: these laws not varying more for the whole than for the beings of which it is composed. Nature is an active living whole, to which all its parts necessarily concur; of which, without their own knowledge, they maintain the activity, the life, and the existence. Nature acts and exists necessarily: all that she contains, necessarily conspires to perpetuate her active existence. This is the decided opinion of Plato, when he says, “matter and necessity are the same thing; this necessity is the mother of the world.” In point of fact, we cannot go beyond this aphorism, matter acts, because it exists; and exists, to act. If it be enquired how, or for why, matter exists? We answer, we know not: but reasoning by analogy, of what we do not know by that which we do, we should be of opinion it exists necessarily, or because it contains within itself a sufficient reason for its existence. In supposing it to be created or produced by a being distinguished from it, or less known than itself, (which it may be, for any thing we know to the contrary,) we must still admit, that this being is necessary, and includes a sufficient reason for his own existence. We have not then removed any of the difficulty, we have not thrown a clearer light upon the subject, we have not advanced a single step; we have simply laid aside a being, of which we know some few of the properties, but of which we are still extremely ignorant, to have recourse to a power, of which it is utterly impossible we can, as long as we are men, form any distinct idea; of which, notwithstanding it may be a truth, we cannot, by any means we possess, demonstrate the existence. As, therefore, these must be at best but speculative points of belief, which each individual, by reason of its obscurity, may contemplate with different optics, under various aspects, they surely ought to be left free for each to judge after his own fashion: the Hindoo can have no just cause of enmity against the Christian for his faith: this has no moral right to question the Mussulman upon his; the numerous sects of each of the various persuasions spread over the face of the earth, ought to make it a creed to look with an eye of complacency on the deviation of the others; and rest upon that great moral axiom, which is strictly conformable to Nature, which contains the whole of man's happiness—“Do not unto another, that which do you not wish another should do unto you;” for it is evident, according to their own doctrines, out of all the variety of systems, one only can be right.

We shall see in the sequel, how much man's imagination labours to form an idea, of the energies of that Nature he has personified, and distinguished from herself: in short, we shall examine some of the ridiculous and pernicious inventions, which, for want of understanding Nature, have been imagined to impede her course, to suspend her eternal laws, to place obstacles to the necessity of things.

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The System of Nature by Baron D’Holbach