"Is the sun the princ.i.p.al cause of the temperature of the earth? We have reason to suppose that it is not. The mean temperature of the earth, at a small depth from the surface, seems constant in summer and in winter, and is probably coeval with its first formation.

"At the planet Mercury, the direct heat of the sun, or its power of causing heat, is six times greater than with us. If we suppose the mean temperature of Mercury to be the same as of the earth, and the planet to be surrounded with an atmosphere, denser than that of the earth, less capable of transmitting heat, or rather the influence of the sun to extricate heat, and at the same time more readily conducting it to keep up an evenness of temperature, may we not suppose the planet Mercury fit for the habitation of men, and the production of vegetables similar to our own?

"At the Georgium Sidus, the direct influence of the sun is 360 times less than at the earth, and the sun is there seen at an angle not much greater than that under which we behold Venus, when nearest. Yet may not the mean temperature of the Georgium Sidus be nearly the same as that of the earth? May not its atmosphere more easily transmit the influence of the sun, and may not the matter of heat be more copiously combined, and more readily extricated, than with us? Whence changes of season similar to our own may take place. Even in the comets we may suppose no great change of temperature takes place, as we know of no cause which will deprive them of their mean temperature, and particularly if we suppose, that on their approach towards the sun, there is a provision for their atmosphere becoming denser. The tails they exhibit, when in the neighbourhood of the sun, seem in some measure to countenance this idea.

"We can hardly suppose the sun, a body three hundred times larger than all the planets together, was created only to preserve the periodic motions, and give light and heat to the planets. Many astronomers have thought that its atmosphere only is luminous, and its body opake, and probably of the same const.i.tution as the planets. Allowing therefore that its luminous atmosphere only extricates heat, we see no reason why the sun itself should not be inhabited(75)."

(75) Brinkley, Elements of Astronomy, Chap. IX.

There is certainly no end to the suppositions that may be made by an ingenious astronomer. May we not suppose that we might do nearly as well altogether without the sun, which it appears is at present of little use to us as to warmth and heat? As to light, the great creator might, for aught we know, find a subst.i.tute; feelers, for example, endued with a certain acuteness of sense: or, at all events, the least imaginable degree of light might answer every purpose to organs adapted to this kind of twilight. In that way the inhabitants of the Georgium Sidus are already sufficiently provided for; they appear to have as little benefit of the light as of the heat of the sun. How the satellites of the distant planets are supplied with light is a mystery, since their princ.i.p.als have scarcely any. Unless indeed, like the sun, they have a luminous atmosphere, competent to enlighten a whole system, themselves being opake. But in truth light in a greater or less degree seems scarcely worthy of a thought, since the inhabitants of the planet Mercury have not their eyes put out by a light, scarcely inferior in radiance to that which is reflected by those plates of burning bra.s.s, with which tyrants in some ages were accustomed to extinguish the sense of vision in their unfortunate victims. The comets also must be a delectable residence; that of 1680 completing its...o...b..t in 576 years, and being at its greatest distance about eleven thousand two hundred millions of miles from the sun, and at its least within less than a third part of the sun's semi-diameter from its surface(76). They must therefore have delightful vicissitudes of light and the contrary; for, as to heat, that is already provided for. Archdeacon Brinkley's postulate is, that these bodies are "possessed by rational beings, and contain animals and vegetables, little different from those with which we are familiar."

(76) Ferguson, Section 93.

Now the only reason we have to believe in these extraordinary propositions, is the knowledge we possess of the divine attributes. From the force of this consideration it is argued that G.o.d will not leave any sensible area of matter unoccupied, and therefore that it is impossible that such vast orbs as we believe surround us even to the extent of infinite s.p.a.ce, should not be "richly stored with rational beings, the capable witnesses of his power, magnificence and benevolence." All difficulties arising from the considerations of light, and heat, and a thousand other obstacles, are to give way to the perfect insight we have as to how the deity will conduct himself in every case that can be proposed. I am not persuaded that this is agreeable to religion; and I am still less convinced that it is compatible with the sobriety and sedateness of common sense.

It is with some degree of satisfaction that I perceive lord Brougham, the reputed author of the Preliminary Discourse to the Library of Useful Knowledge, at the same time that he states the dimensions and distances of the heavenly bodies in the usual way, says not a word of their inhabitants.

It is somewhat remarkable that, since the commencement of the present century, four new planets have been added to those formerly contained in the enumeration of the solar system. They lie between the planets Mars and Jupiter, and have been named Vesta, Juno, Ceres and Pallas. Brinkley speaks of them in this manner. "The very small magnitudes of the new planets Ceres and Pallas, and their nearly equal distances from the sun, induced Dr. Olbers, who discovered Pallas in 1802, nearly in the same place where he had observed Ceres a few months before, to conjecture that they were fragments of a larger planet, which had by some unknown cause been broken to pieces. It follows from the law of gravity, by which the planets are retained in their orbits, that each fragment would again, after every revolution about the sun, pa.s.s nearly through the place in which the planet was when the catastrophe happened, and besides the orbit of each fragment would intersect the continuation of the line joining this place and the sun. Thence it was easy to ascertain the two particular regions of the heavens through which all these fragments would pa.s.s. Also, by carefully noting the small stars thereabout, and examining them from time to time, it might be expected that more of the fragments would be discovered.--M. Harding discovered the planet Juno in one of these regions; and Dr. Olbers himself also, by carefully examining them (the small stars) from time to time, discovered Vesta."

These additions certainly afford us a new epoch in the annals of the solar system, and of astronomy itself. It is somewhat remarkable, that Herschel, who in the course of his observations traced certain nebulae, the light from which must have been two millions of years in reaching the earth, should never have remarked these planets, which, so to speak, lay at his feet. It reminds one of Esop's astrologer, who, to the amus.e.m.e.nt of his ignorant countrymen, while he was wholly occupied in surveying the heavens, suddenly found himself plunged in a pit. These new planets also we are told are fragments of a larger planet: how came this larger planet never to have been discovered?

Till Herschel's time we were content with six planets and the sun, making up the cabalistical number seven. He added another. But these four new ones entirely derange the scheme. The astronomers have not yet had opportunity to digest them into their places, and form new worlds of them. This is all unpleasant. They are, it seems, "fragments of a larger planet, which had by some unknown cause been broken to pieces." They therefore are probably not inhabited. How does this correspond with the goodness of G.o.d, which will suffer no ma.s.s of matter in his creation to remain unoccupied? Herschel talks at his ease of whole systems, suns with all their attendant planets, being consigned to destruction. But here we have a catastrophe happening before our eyes, and cannot avoid being shocked by it. "G.o.d does nothing in vain." For which of his lofty purposes has this planet been broken to pieces, and its fragments left to deform the system of which we are inhabitants; at least to humble the pride of man, and laugh to scorn his presumption? Still they perform their revolutions, and obey the projectile and gravitating forces, which have induced us to people ten thousand times ten thousand worlds. It is time, that we should learn modesty, to revere in silence the great cause to which the universe is indebted for its magnificence, its beauty and harmony, and to acknowledge that we do not possess the key that should unlock the mysteries of creation.

One of the most important lessons that can be impressed on the human mind, is that of self-knowledge and a just apprehension of what it is that we are competent to achieve. We can do much. We are capable of much knowledge and much virtue. We have patience, perseverance and subtlety.

We can put forth considerable energies, and nerve ourselves to resist great obstacles and much suffering. Our ingenuity is various and considerable. We can form machines, and erect mighty structures. The invention of man for the ease of human life, and for procuring it a mult.i.tude of pleasures and accommodations, is truly astonishing. We can dissect the human frame, and anatomise the mind. We can study the scene of our social existence, and make extraordinary improvements in the administration of justice, and in securing to ourselves that germ of all our n.o.blest virtues, civil and political liberty. We can study the earth, its strata, its soil, its animals, and its productions, "from the cedar that is in Lebanon, to the hyssop that springeth out of the wall."

But man is not omnipotent. If he aspires to be worthy of honour, it is necessary that he should compute his powers, and what it is they are competent to achieve. The globe of earth, with "all that is therein," is our estate and our empire. Let us be content with that which we have. It were a pitiful thing to see so n.o.ble a creature struggling in a field, where it is impossible for him to distinguish himself, or to effect any thing real. There is no situation in which any one can appear more little and ludicrous, than when he engages in vain essays, and seeks to accomplish that, which a moment's sober thought would teach him was utterly hopeless.

Even astronomy is to a certain degree our own. We can measure the course of the sun, and the orbits of the planets. We can calculate eclipses.

We can number the stars, a.s.sign to them their places, and form them into what we call constellations. But, when we pretend to measure millions of miles in the heavens, and to make ourselves acquainted with the inhabitants of ten thousand times ten thousand worlds and the accommodations which the creator has provided for their comfort and felicity, we probably engage in something more fruitless and idle, than the pigmy who should undertake to bend the bow of Ulysses, or strut and perform the office of a warrior clad in the armour of Achilles.

How beautiful is the "firmament; this majestical roof fretted with golden fire!" Let us beware how we mar the magnificent scene with our interpolations and commentaries! Simplicity is of the essence of the truly great. Let us look at the operations of that mighty power from which we ourselves derive our existence, with humility and reverential awe! It may well become us. Let us not "presume into the heaven of heavens," unbidden, unauthorised guests! Let us adopt the counsel of the apostle, and allow no man to "spoil us through vain philosophy." The business of human life is serious; the useful investigations in which we may engage are multiplied. It is excellent to see a rational being conscious of his genuine province, and not idly wasting powers adapted for the n.o.blest uses in unmeasured essays and ill-concocted attempts.

ESSAY XXII. OF THE MATERIAL UNIVERSE.

In the preceding Essay I have referred to the theory of Berkeley, whose opinion is that there is no such thing as matter in the sense in which it is understood by the writers on natural philosophy, and that the whole of our experience in that respect is the result of a system of accidents without an intelligible subject, by means of which antecedents and consequents flow on for ever in a train, the past succession of which man is able to record, and the future in many cases he is qualified to predict and to act upon.

An argument more palpable and popular than that of Berkeley in favour of the same hypothesis, might be deduced from the points recapitulated in that Essay as delivered by Locke and Newton. If what are vulgarly denominated the secondary qualities of matter are in reality nothing but sensations existing in the human mind, then at any rate matter is a very different thing from what it is ordinarily apprehended to be. To which I add, in the second place, that, if matter, as is stated by Newton, consists in so much greater a degree of pores than solid parts, that the absolute particles contained in the solar system might, for aught we know, he contained in a nutsh.e.l.l(77), and that no two ever touched each other, or approached so near that they might not be brought nearer, provided a sufficient force could be applied for that purpose,--and if, as Priestley teaches, all that we observe is the result of successive spheres of attraction and repulsion, the centre of which is a mathematical point only, we then certainly come very near to a conclusion, which should banish matter out of the theatre of real existences(78).

(77) See above, Essay XXI.

(78) See above, Essay XXI.

But the extreme subtleties of human intellect are perhaps of little further use, than to afford an amus.e.m.e.nt to persons of curious speculation, and whose condition in human society procures them leisure for such enquiries. The same thing happens here, as in the subject of my Twelfth Essay, on the Liberty of Human Actions. The speculator in his closet is one man: the same person, when he comes out of his retirement, and mixes in intercourse with his fellow-creatures, is another man.

The necessarian, when he reasons on the everlasting concatenation of antecedents and consequents, proves to his own apprehension irrefragably, that he is a pa.s.sive instrument, acted upon, and acting upon other things, in turn, and that he can never disengage himself from the operation of the omnipotent laws of physical nature, and the impulses of other men with whom he is united in the ties of society. But no sooner does this acute and ingenious reasoner come into active life and the intercourse of his fellowmen, than all these fine-drawn speculations vanish from his recollection. He regards himself and other men as beings endowed with a liberty of action, as possessed of a proper initiative power, and free to do a thing or not to do it, without being subject to the absolute and irresistible constraint of motives. It is from this internal and indefeasible sense of liberty, that we draw all our moral energies and enthusiasm, that we persevere heroically in defiance of obstacles and discouragements, that we praise or blame the actions of others, and admire the elevated virtues of the best of our contemporaries, and of those whose achievements adorn the page of history.

It is in a manner of precisely the same sort as that which prevails in the philosophical doctrines of liberty and necessity, that we find ourselves impelled to feel on the question of the existence of the material universe. Berkeley, and as many persons as are persuaded by his or similar reasonings, feel satisfied in speculation that there is no such thing as matter in the sense in which it is understood by the writers on natural philosophy, and that all our notions of the external and actual existence of the table, the chair, and the other material substances with which we conceive ourselves to be surrounded, of woods, and mountains, and rivers, and seas, are mere prejudice and misconception. All this is very well in the closet, and as long as we are involved in meditation, and remain abstracted from action, business, and the exertion of our limbs and corporal faculties. But it is too fine for the realities of life. Berkeley, and the most strenuous and spiritualised of his followers, no sooner descend from the high tower of their speculations, submit to the necessities of their nature, and mix in the business of the world, than they become impelled, as strongly as the necessarian in the question of the liberty of human actions, not only to act like other men, but even to feel just in the same manner as if they had never been acquainted with these abstractions. A table then becomes absolutely a table, and a chair a chair: they are "fed with the same food, hurt by the same weapons, and warmed and cooled by the same summer and winter," as other men: and they make use of the refreshments which nature requires, with as true an orthodoxy, and as credulous a temper, as he who was never a.s.sailed with such refinements. Nature is too strong, to be prevailed on to retire, and give way to the authority of definitions and syllogistical deduction.

But, when we have granted all this, it is however a mistake to say, that these "subtleties of human intellect are of little further use, than to afford an amus.e.m.e.nt to persons of curious speculation(79)." We have seen, in the case of the doctrine of philosophical necessity(80), that, though it can never form a rule for the intercourse between man and man, it may nevertheless be turned to no mean advantage. It is calculated to inspire us with temperance and toleration. It tends impressively to evince to us, that this scene of things is but like the shadows which pa.s.s before us in a magic lanthorn, and that, after all, men are but the tools, not the masters, of their fate. It corrects the illusions of life, much after the same manner as the spectator of a puppet-shew is enlightened, who should be taken within the curtain, and shewn how the wires are pulled by the master, which produce all the turmoil and strife that before riveted our attention. It is good for him who would arrive at all the improvement of which our nature is capable, at one time to take his place among the literal beholders of the drama, and at another to go behind the scenes, and remark the deceptions in their original elements, and the actors in their proper and natural costume.

(79) See above, Essay XXII.

(80) See above, Essay XII.

And, as in the question of the liberty of human actions, so in that of the reality of the material universe, it is a privilege not to be despised, that we are so formed as to be able to dissect the subject that is submitted to our examination, and to strip the elements of which this sublunary scene is composed, of the disguise in which they present themselves to the vulgar spectator. It is little, after all, that we are capable to know; and the man of heroic mind and generous enterprise, will not refuse the discoveries that are placed within his reach. The subtleties of grammar are as the porch, which leads from the knowledge of words to the knowledge of things. The subtleties of mathematics defecate the grossness of our apprehension, and supply the elements of a sounder and severer logic. And in the same manner the faculty which removes the illusions of external appearance, and enables us to "look into the seeds of time," is one which we are bound to estimate at its genuine value. The more we refine our faculties, other things equal, the wiser we grow: we are the more raised above the thickness of the atmosphere that envelops our fellow-mortals, and are made partakers of a nature superhuman and divine.

There is a curious question that has risen out of this proposition of Berkeley, of the supposed illusion we suffer in our conceptions of the material universe. It has been said, "Well then, I am satisfied that the chairs, the tables, and the other material substances with which I conceive myself to be surrounded, are not what they appear to be, but are merely an eternal chain of antecedents and consequents, going on according to what Leibnitz calls a 'preestablished harmony,' and thus furnishing the ground of the speculations which mortals cherish, and the motives of their proceeding. But, if thus, in the ordinary process of human affairs, we believe in matter, when in reality there is no such thing as matter, how shall we p.r.o.nounce of mind, and the things which happen to us in our seeming intercourse with our fellow-men, and in the complexities of love and hatred, of kindred and friendship, of benevolence and misanthropy, of robbery and murder, and of the wholesale ma.s.sacre of thousands of human beings which are recorded in the page of history? We absolutely know nothing of the lives and actions of others but through the medium of material impulse. And, if you take away matter, the bodies of our fellow-men, does it not follow by irresistible consequence that all knowledge of their minds is taken away also? Am not I therefore (the person engaged in reading the present Essay) the only being in existence, an entire universe to myself?"

Certainly this is a very different conclusion from any that Berkeley ever contemplated. In the very t.i.tle of the Treatise in which his notions on this subject are unfolded, he professes his purpose to be to remove "the grounds of scepticism, atheism and irreligion." Berkeley was a sincere Christian, and a man of the most ingenuous dispositions. Pope, in the Epilogue to his Satires, does not hesitate to ascribe to him "every virtue under heaven." He was for twenty years a prelate of the Protestant church. And, though his personal sentiments were in the highest degree philanthropical and amiable, yet, in his most diffusive production, ent.i.tled The Minute Philosopher, he treats "those who are called Free Thinkers" with a scorn and disdain, scarcely to be reconciled with the spirit of Christian meekness.

There are examples however, especially in the fields of controversy, where an adventurous speculatist has been known to lay down premises and principles, from which inferences might be fairly deduced, incompatible with the opinions entertained by him who delivered them. It may therefore be no unprofitable research to enquire how far the creed of the non-existence of matter is to be regarded as in truth and reality countenancing the inference which has just been recited.

The persons then, who refine with Berkeley upon the system of things so far, as to deny that there is any such thing as matter in the sense in which it is understood by the writers on natural philosophy, proceed on the ground of affirming that we have no reason to believe that the causes of our sensations have an express resemblance to the sensations themselves(81). That which gives us a sensation of colour is not itself coloured: and the same may be affirmed of the sensations of hot and cold, of sweet and bitter, and of odours offensive or otherwise. The immaterialist proceeds to say, that what we call matter has been strewn to be so exceedingly porous, that, for any thing we know, all the solid particles in the universe might be contained in a nutsh.e.l.l, that there is no such thing in the external world as actual contact, and that no two particles of matter were ever so near to each other, but that they might be brought nearer, if a sufficient force could be applied for that purpose. From these premises it seems to follow with sufficient evidence, that the causes of our sensations, so far as the material universe is concerned, bear no express resemblance to the sensations themselves.

(81) See above, Essay XXI.

How then does the question stand with relation to mind? Are those persons who deny the existence of matter, reduced, if they would be consistent in their reasonings, to deny, each man for himself, that he has any proper evidence of the existence of other minds than his own?

He denies, while he has the sensation of colour, that there exists colour out of himself, unless in thinking and percipient beings const.i.tuted in a manner similar to that in which he is const.i.tuted. And the same of the sensations of hot and cold, sweet and bitter, and odours offensive or otherwise. He affirms, while he has the sensation of length, breadth and thickness, that there is no continuous substance out of himself, possessing the attributes of length, breadth and thickness in any way similar to the sensation of which he is conscious.

He professes therefore that he has no evidence, arising from his observation of what we call matter, of the actual existence of a material world. He looks into himself, and all he finds is sensation; but sensation cannot be a property of inert matter. There is therefore no a.s.signable a.n.a.logy between the causes of his sensations, whatever they may be, and the sensations themselves; and the material world, such as we apprehend it, is the mere creature of his own mind.

Let us next consider how this question stands as to the conceptions he entertains respecting the minds of other men. That which gives him the sensation of colour, is not any thing coloured out of himself; and that which gives him the sensation of length, breadth and thickness, is not any thing long, broad and thick in a manner corresponding with the impression he receives. There is nothing in the nature of a parallel, a type and its archetype, between that which is without him and that which is within, the impresser and the impression. This is the point supposed to be established by Locke and Newton, and by those who have followed the reasonings of these philosophers into their remotest consequences.

But the case is far otherwise in the impressions we receive respecting the minds of other men. In colour it has been proved by these authors that there is no express correspondence and a.n.a.logy between the cause of the sensation and the sensation. They are not part and counterpart.

But in mind there is a precise resemblance and a.n.a.logy between the conceptions we are led to entertain respecting other men, and what we know of ourselves. I and my a.s.sociate, or fellow-man, are like two instruments of music constructed upon the same model. We have each of us, so to speak, the three great divisions of sound, base, tenor and treble. We have each the same number of keys, capable of being struck, consecutively or with alternations, at the will of the master. We can utter the same sound or series of sounds, or sounds of a different character, but which respond to each other. My neighbour therefore being of the same nature as myself, what pa.s.ses within me may be regarded as amounting to a commanding evidence that he is a real being, having a proper and independent existence.

There is further something still more impressive and irresistible in the notices I receive respecting the minds of other men. The sceptics whose reasonings I am here taking into consideration, admit, each man for himself, the reality of his own existence. There is such a thing therefore as human nature; for he is a specimen of it. Now the idea of human nature, or of man, is a very complex thing. He is in the first place the subject of sensible impressions, however these impressions are communicated to him. He has the faculties of thinking and feeling. He is subject to the law of the a.s.sociation of ideas, or, in other words, any one idea existing in his mind has a tendency to call up the ideas of other things which have been connected with it in his first experience.

He has, be it delusive or otherwise, the sense of liberty of action.

But we will go still further into detail as to the nature of man.

Our lives are carried forward by the intervention of what we call meat, drink and sleep. We are liable to the accidents of health and sickness.

We are alternately the recipients of joy and sorrow, of cheerfulness and melancholy. Our pa.s.sions are excited by similar means, whether of love or hatred, complacency or indignation, sympathy or resentment. I could fill many pages with a description of the properties or accidents, which belong to man as such, or to which he is liable.