Scientific Essays and Lectures Part 4

He has, at first sight, a very simple measure--that of denudation.

He sees that the glen is now being eaten out by a little stream, the product of innumerable springs which arise along its sides, and which are fed entirely by the rain on the moors above. He finds, on observation, that this stream brings down some ten cubic yards of sand and gravel, on an average, every year. The actual quant.i.ty of earth which has been removed to make the glen may be several million cubic yards. Here is an easy sum in arithmetic. At the rate of ten cubic yards a-year, the stream has taken several hundred thousand years to make the glen.

You will observe that this result is obtained by mere common sense.

He has a right to a.s.sume that the stream originally began the glen, because he finds it in the act of enlarging it; just as much right as he has to a.s.sume, if he find a hole in his pocket, and his last coin in the act of falling through it, that the rest of his money has fallen through the same hole. It is a sufficient cause, and the simplest. A number of observations as to the present rate of denudation, and a sum which any railroad contractor can do in his head, to determine the solid contents of the valley, are all that are needed. The method is that of science: but it is also that of simple common sense. You will remember, therefore, that this is no mere theory or hypothesis, but a pretty fair and simple conclusion from palpable facts; that the probability lies with the belief that the glen is some hundreds of thousands of years old; that it is not the observer's business to prove it further, but other persons' to disprove it, if they can.

But does the matter end here? No. And, for certain reasons, it is good that it should not end here.

The observer, if he be a cautious man, begins to see if he can disprove his own conclusions; moreover, being human, he is probably somewhat awed, if not appalled, by his own conclusion. Hundreds of thousands of years spent in making that little glen! Common sense would say that the longer it took to make, the less wonder there was in its being made at last: but the instinctive human feeling is the opposite. There is in men, and there remains in them, even after they are civilised, and all other forms of the dread of Nature have died out in them, a dread of size, of vast s.p.a.ce, of vast time; that latter, mind, being always imagined as s.p.a.ce, as we confess when we speak instinctively of a s.p.a.ce of time. They will not understand that size is merely a relative, not an absolute term; that if we were a thousand times larger than we are, the universe would be a thousand times smaller than it is; that if we could think a thousand times faster than we do, time would be a thousand times longer than it is; that there is One in whom we live, and move, and have our being, to whom one day is as a thousand years, and a thousand years as one day. I believe this dread of size to be merely, like all other superst.i.tions, a result of bodily fear; a development of the instinct which makes a little dog run away from a big dog. Be that as it may, every observer has it; and so the man's conclusion seems to him strange, doubtful: he will reconsider it.

Moreover, if he be an experienced man, he is well aware that first guesses, first hypotheses, are not always the right ones; and if he be a modest man, he will consider the fact that many thousands of thoughtful men in all ages, and many thousands still, would say, that the glen can only be a few thousand, or possibly a few hundred, years old. And he will feel bound to consider their opinion; as far as it is, like his own, drawn from facts, but no further.

So he casts about for all other methods by which the glen may have been produced, to see if any one of them will account for it in a shorter time.

1. Was it made by an earthquake? No; for the strata on both sides are identical, at the same level, and in the same plane.

2. Or by a mighty current? If so, the flood must have run in at the upper end, before it ran out at the lower. But nothing has run in at the upper end. All round above are the undisturbed gravel- beds of the horizontal moor, without channel or depression.

3. Or by water draining off a vast flat as it was upheaved out of the sea? That is a likely guess. The valley at its upper end spreads out like the fingers of a hand, as the gullies in tide-muds do.

But that hypothesis will not stand. There is no vast unbroken flat behind the glen. Right and left of it are other similar glens, parted from it by long narrow ridges: these also must be explained on the same hypothesis; but they cannot. For there could not have been surface-drainage to make them all, or a tenth of them. There are no other possible hypotheses; and so he must fall back on the original theory--the rain, the springs, the brook; they have done it all, even as they are doing it this day.

But is not that still a hasty a.s.sumption? May not their denuding power have been far greater in old times than now?

Why should it? Because there was more rain then than now? That he must put out of court; there is no evidence of it whatsoever.

Because the land was more friable originally? Well, there is a great deal to be said for that. The experience of every countryman tells him that bare or fallow land is more easily washed away than land under vegetation. And no doubt, when these gravels and sands rose from the sea, they were barren for hundreds of years. He has some measure of the time required, because he can tell roughly how long it takes for sands and shingles left by the sea to become covered with vegetation. But he must allow that the friability of the land must have been originally much greater than now, for hundreds of years.

But again, does that fact really cut off any great s.p.a.ce of time from his hundreds of thousands of years? For when the land first rose from the sea, that glen was not there. Some slight bay or bend in the sh.o.r.e determined its site. That stream was not there. It was split up into a million little springs, oozing side by side from the sh.o.r.e, and having each a very minute denuding power, which kept continually increasing by combination as the glen ate its way inwards, and the rainfall drained by all these little springs was collected into the one central stream. So that when the ground being bare was most liable to be denuded, the water was least able to do it; and as the denuding power of the water increased, the land, being covered with vegetation, became more and more able to resist it. All this he has seen, going on at the present day in the similar gullies worn in the soft strata of the South Hampshire coast; especially round Bournemouth.

So the two disturbing elements in the calculation may be fairly set off against each other, as making a difference of only a few thousands or tens of thousands of years either way; and the age of the glen may fairly be, if not a million years, yet such a length of years as mankind still speak of with bated breath, as if forsooth it would do them some harm.

I trust that every scientific man in this room will agree with me, that the imaginary squire or ploughman would have been conducting his investigation strictly according to the laws of the Baconian philosophy. You will remark, meanwhile, that he has not used a single scientific term, or referred to a single scientific investigation; and has observed nothing and thought nothing, which might not have been observed and thought by any one who chose to use his common sense, and not to be afraid.

But because he has come round, after all this further investigation, to something very like his first conclusion, was all that further investigation useless? No--a thousand times, no. It is this very verification of hypotheses which makes the sound ones safe, and destroys the unsound. It is this struggle with all sorts of superst.i.tions which makes science strong and sure, and her march irresistible, winning ground slowly, but never receding from it. It is this buffeting of adversity which compels her not to rest dangerously upon the shallow sand of first guesses, and single observations; but to strike her roots down, deep, wide, and interlaced, into the solid ground of actual facts.

It is very necessary to insist on this point. For there have been men in all past ages--I do not say whether there are any such now, but I am inclined to think that there will be hereafter--men who have tried to represent scientific method as something difficult, mysterious, peculiar, unique, not to be attained by the unscientific ma.s.s; and this not for the purpose of exalting science, but rather of discrediting her. For as long as the ma.s.ses, educated or uneducated, are ignorant of what scientific method is, they will look on scientific men, as the middle age looked on necromancers, as a privileged, but awful and uncanny caste, possessed of mighty secrets; who may do them great good, but may also do them great harm. Which belief on the part of the ma.s.ses will enable these persons to instal themselves as the critics of science, though not scientific men themselves: and--as Shakespeare has it--to talk of Robin Hood, though they never shot in his bow. Thus they become mediators to the ma.s.ses between the scientific and the unscientific worlds. They tell them--You are not to trust the conclusions of men of science at first hand. You are not fit judges of their facts or of their methods. It is we who will, by a cautious eclecticism, choose out for you such of their conclusions as are safe for you; and them we will advise you to believe. To the scientific man, on the other hand, as often as anything is discovered unpleasing to them, they will say, imperiously and e cathedra--Your new theory contradicts the established facts of science. For they will know well that whatever the men of science think of their a.s.sertion, the ma.s.ses will believe it; totally unaware that the speakers are by their very terms showing their ignorance of science; and that what they call established facts scientific men call merely provisional conclusions, which they would throw away to-morrow without a pang were the known facts explained better by a fresh theory, or did fresh facts require one.

This has happened too often. It is in the interest of superst.i.tion that it should happen again; and the best way to prevent it surely is to tell the ma.s.ses--Scientific method is no peculiar mystery, requiring a peculiar initiation. It is simply common sense, combined with uncommon courage, which includes uncommon honesty and uncommon patience; and if you will be brave, honest, patient, and rational, you will need no mystagogues to tell you what in science to believe and what not to believe; for you will be just as good judges of scientific facts and theories as those who a.s.sume the right of guiding your convictions. You are men and women: and more than that you need not be.

And let me say that the man of our days whose writings exemplify most thoroughly what I am going to say is the justly revered Mr.

Thomas Carlyle.

As far as I know he has never written on any scientific subject.

For aught I am aware of, he may know nothing of mathematics or chemistry, of comparative anatomy or geology. For aught I am aware of, he may know a great deal about them all, and, like a wise man, hold his tongue, and give the world merely the results in the form of general thought. But this I know: that his writings are instinct with the very spirit of science; that he has taught men, more than any living man, the meaning and end of science; that he has taught men moral and intellectual courage; to face facts boldly, while they confess the divineness of facts; not to be afraid of Nature, and not to worship Nature; to believe that man can know truth; and that only in as far as he knows truth can he live worthily on this earth. And thus he has vindicated, as no other man in our days has done, at once the dignity of Nature and the dignity of spirit. That he would have made a distinguished scientific man, we may be as certain from his writings as we may be certain, when we see a fine old horse of a certain stamp, that he would have made a first-cla.s.s hunter, though he has been unfortunately all his life in harness. Therefore, did I try to train a young man of science to be true, devout, and earnest, accurate and daring, I should say--Read what you will: but at least read Carlyle. It is a small matter to me--and I doubt not to him--whether you will agree with his special conclusions: but his premises and his method are irrefragable; for they stand on the "voluntatem Dei in rebus revelatam"--on fact and common sense.

And Mr. Carlyle's writings, if I am correct in my estimate of them, will afford a very sufficient answer to those who think that the scientific habit of mind tends to irreverence.

Doubtless this accusation will always be brought against science by those who confound reverence with fear. For from blind fear of the unknown, science does certainly deliver man. She does by man as he does by an unbroken colt. The colt sees by the road side some quite new object--a cast-away boot, an old kettle, or what not. What a fearful monster! What unknown terrific powers may it not possess!

And the colt shies across the road, runs up the bank, rears on end; putting itself thereby, as many a man does, in real danger. What cure is there? But one: experience. So science takes us, as we should take the colt, gently by the halter; and makes us simply smell at the new monster; till after a few trembling sniffs, we discover, like the colt, that it is not a monster, but a kettle.

Yet I think, if we sum up the loss and gain, we shall find the colt's character has gained, rather than lost, by being thus disabused. He learns to subst.i.tute a very rational reverence for the man who is breaking him in, for a totally irrational reverence for the kettle; and becomes thereby a much wiser and more useful member of society, as does the man when disabused of his superst.i.tions.

From which follows one result. That if science proposes--as she does--to make men brave, wise, and independent, she must needs excite unpleasant feelings in all who desire to keep men cowardly, ignorant, and slavish. And that too many such persons have existed in all ages is but too notorious. There have been from all time, goetai, quacks, powwow men, rain-makers, and necromancers of various sorts, who having for their own purposes set forth partial, ill- grounded, fantastic, and frightful interpretations of nature, have no love for those who search after a true, exact, brave, and hopeful one. And therefore it is to be feared, or hoped, that science and superst.i.tion will to the world's end remain irreconcilable and internecine foes.

Conceive the feelings of an old Lapland witch, who has had for the last fifty years all the winds in a sealskin bag, and has been selling fair breezes to northern skippers at so much a puff, a.s.serting her powers so often, poor old soul, that she has got to half believe them herself--conceive, I say, her feelings at seeing her customers watch the Admiralty storm-signals, and con the weather reports in The Times. Conceive the feelings of Sir Samuel Baker's African friend, Katchiba, the rain-making chief, who possessed a whole houseful of thunder and lightning--though he did not, he confessed, keep it in a bottle as they do in England--if Sir Samuel had had the means, and the will, of giving to Katchiba's Negros a course of lectures on electricity, with appropriate experiments, and a real bottle full of real lightning among the foremost.

It is clear that only two methods of self-defence would have been open to the rain-maker: namely, either to kill Sir Samuel, or to buy his real secret of bottling the lightning, that he might use it for his own ends. The former method--that of killing the man of science--was found more easy in ancient times; the latter in these modern ones. And there have been always those who, too good-natured to kill the scientific man, have patronised knowledge, not for its own sake, but for the use which may be made of it; who would like to keep a tame man of science, as they would a tame poet, or a tame parrot; who say--Let us have science by all means, but not too much of it. It is a dangerous thing; to be doled out to the world, like medicine, in small and cautious doses. You, the scientific man, will of course freely discover what you choose. Only do not talk too loudly about it: leave that to us. We understand the world, and are meant to guide and govern it. So discover freely: and meanwhile hand over your discoveries to us, that we may instruct and edify the populace with so much of them as we think safe, while we keep our position thereby, and in many cases make much money by your science. Do that, and we will patronise you, applaud you, ask you to our houses; and you shall be clothed in purple and fine linen, and fare sumptuously with us every day. I know not whether these latter are not the worst enemies which science has. They are often such excellent, respectable, orderly, well-meaning persons. They desire so sincerely that everyone should be wise: only not too wise. They are so utterly unaware of the mischief they are doing.

They would recoil with horror if they were told they were so many Iscariots, betraying Truth with a kiss.

But science, as yet, has withstood both terrors and blandishments.

In old times she endured being imprisoned and slain. She came to life again. Perhaps it was the will of Him in whom all things live, that she should live. Perhaps it was His spirit which gave her life.

She can endure, too, being starved. Her votaries have not as yet cared much for purple and fine linen, and sumptuous fare. There are a very few among them who, joining brilliant talents to solid learning, have risen to deserved popularity, to t.i.tles, and to wealth. But even their labours, it seems to me, are never rewarded in any proportion to the time and the intellect spent on them, nor to the benefits which they bring to mankind; while the great majority, unpaid and unknown, toil on, and have to find in science her own reward. Better, perhaps, that it should be so. Better for science that she should be free, in holy poverty, to go where she will and say what she knows, than that she should be hired out at so much a year to say things pleasing to the many, and to those who guide the many. And so, I verily believe, the majority of scientific men think. There are those among them who have obeyed very faithfully St. Paul's precept: "No man that warreth entangleth himself with the affairs of this life." For they have discovered that they are engaged in a war--a veritable war--against the rulers of darkness, against ignorance and its twin children, fear and cruelty. Of that war they see neither the end nor even the plan.

But they are ready to go on; ready, with Socrates, "to follow reason whithersoever it leads;" and content, meanwhile, like good soldiers in a campaign, if they can keep tolerably in a line, and use their weapons, and see a few yards ahead of them through the smoke and the woods. They will come out somewhere at last; they know not where nor when: but they will come out at last, into the daylight and the open field; and be told then--perhaps to their own astonishment--as many a gallant soldier has been told, that by simply walking straight on, and doing the duty which lay nearest them, they have helped to win a great battle, and slay great giants, earning the thanks of their country and of mankind.

And, meanwhile, if they get their shilling a-day of fighting-pay, they are content. I had almost said, they ought to be content. For science is, I verily believe, like virtue, its own exceeding great reward. I can conceive few human states more enviable than that of the man to whom, panting in the foul laboratory, or watching for his life under the tropic forest, Isis shall for a moment lift her sacred veil, and show him, once and for ever, the thing he dreamed not of; some law, or even mere hint of a law, explaining one fact; but explaining with it a thousand more, connecting them all with each other and with the mighty whole, till order and meaning shoots through some old Chaos of scattered observations.

Is not that a joy, a prize, which wealth cannot give, nor poverty take away? What it may lead to, he knows not. Of what use it may become, he knows not. But this he knows, that somewhere it must lead; of some use it will be. For it is a truth; and having found a truth, he has exorcised one more of the ghosts which haunt humanity.

He has left one object less for man to fear; one object more for man to use. Yes, the scientific man may have this comfort, that whatever he has done, he has done good; that he is following a mistress who has never yet conferred aught but benefits on the human race.

What physical science may do hereafter I know not; but as yet she has done this:

She has enormously increased the wealth of the human race; and has therefore given employment, food, existence, to millions who, without science, would either have starved or have never been born.

She has shown that the dictum of the early political economists, that population has a tendency to increase faster than the means of subsistence, is no law of humanity, but merely a tendency of the barbaric and ignorant man, which can be counteracted by increasing manifold by scientific means his powers of producing food. She has taught men, during the last few years, to foresee and elude the most destructive storms; and there is no reason for doubting, and many reasons for hoping, that she will gradually teach men to elude other terrific forces of nature, too powerful and too seemingly capricious for them to conquer. She has discovered innumerable remedies and alleviations for pains and disease. She has thrown such light on the causes of epidemics, that we are able to say now that the presence of cholera--and probably of all zymotic diseases--in any place, is usually a sin and a shame, for which the owners and authorities of that place ought to be punishable by law, as destroyers of their fellow-men; while for the weak, for those who, in the barbarous and semi-barbarous state--and out of that last we are only just emerging--how much has she done; an earnest of much more which she will do? She has delivered the insane--I may say by the scientific insight of one man, more worthy of t.i.tles and pensions than nine-tenths of those who earn them--I mean the great and good Pinel--from hopeless misery and torture into comparative peace and comfort, and at least the possibility of cure. For children, she has done much, or rather might do, would parents read and perpend such books as Andrew Combe's and those of other writers on physical education. We should not then see the children, even of the rich, done to death piecemeal by improper food, improper clothes, neglect of ventilation and the commonest measures for preserving health. We should not see their intellects stunted by Procrustean attempts to teach them all the same accomplishments, to the neglect, most often, of any sound practical training of their faculties. We should not see slight indigestion, or temporary rushes of blood to the head, condemned and punished as sins against Him who took up little children in His arms and blessed them.

But we may have hope. When we compare education now with what it was even forty years ago, much more with the stupid brutality of the monastic system, we may hail for children, as well as for grown people, the advent of the reign of common sense.

And for woman--What might I not say on that point? But most of it would be fitly discussed only among physicians and biologists: here I will say only this: Science has exterminated, at least among civilised nations, witch-manias. Women--at least white women--are no longer tortured or burnt alive from man's blind fear of the unknown. If science had done no more than that, she would deserve the perpetual thanks and the perpetual trust, not only of the women whom she has preserved from agony, but the men whom she has preserved from crime.

These benefits have already accrued to civilised men, because they have lately allowed a very few of their number peaceably to imitate Mr. Rarey, and find out what nature--or rather, to speak at once reverently and accurately, He who made nature--is thinking of, and obey the "voluntatem Dei in rebus revelatam." This science has done, while yet in her infancy. What she will do in her maturity, who dare predict? At least, in the face of such facts as these, those who bid us fear, or restrain, or mutilate science, bid us commit an act of folly, as well as of ingrat.i.tude, which can only harm ourselves. For science has as yet done nothing but good. Will any one tell me what harm it has ever done? When any one will show me a single result of science, of the knowledge of and use of physical facts, which has not tended directly to the benefit of mankind, moral and spiritual, as well as physical and economic--then I shall be tempted to believe that Solomon was wrong when he said that the one thing to be sought after on earth, more precious than all treasure, she who has length of days in her right hand, and in her left hand riches and honour, whose ways are ways of pleasantness and all her paths are peace, who is a tree of life to all who lay hold on her, and makes happy every one who retains her, is--as you will see if you will yourselves consult the pa.s.sage--that very Wisdom--by which G.o.d has founded the earth; and that very Understanding--by which He has established the heavens.

THOUGHTS IN A GRAVEL-PIT {262}

Ladies and gentlemen, we may of course think of anything which we choose in a gravel-pit, as we may anywhere else. Thought is free: at least so we fancy.

But the most right sort of thought, after all, is thought about what lies nearest us; not always, but surely once in a way, that we may understand something of everyday objects. And therefore it may be well worth our while to go once into a gravel-pit, and think about it, till we have learnt what a gravel-pit is.

Learnt what a gravel-pit is? Everybody knows.

If it be so, everybody knows more than I know. We all know a gravel-pit when we see one; but we do not all know what we see. I do not know. I know a little; a few sc.r.a.ps of fact about these pits round here, though about no others. Were I to go into a pit a hundred miles, even fifty miles off, I could tell you nothing certain about it; perhaps might make a dozen mistakes. But what I know, with tolerable certainty, about the pits round here, I wish to tell you to-night.

But why? You do not need, one in ten of you, to know anything about gravel, unless you be highway surveyor, or have a garden-walk to make; and then someone will easily tell you where the best gravel is to be got, at so much a load.

Very true; but you come here to-night to instruct yourselves; that is, to learn, if you can, something more about the world you live in; something more about G.o.d who made the world.