A fool who, after plain warning, persists in dosing himself with dangerous drugs should be free to do so, for his death is a benefit to the race in general.

As for science and religion, the known and admitted facts are few and plain enough. All that the parsons say is unproved. All that the doctors say is disproved. That’s the only difference between science and religion…

Biological disciplines tend to guide research into certain channels. One consequence is that disciplines are apt to become parochial, or at least to develop blind spots, for example, to treat some questions as “interesting” and to dismiss others as “uninteresting.” As a consequence, readily accessible but unworked areas of genuine biological interest often lie in plain sight but untouched within one discipline while being heavily worked in another. For example, historically insect physiologists have paid relatively little attention to the behavioral and physiological control of body temperature and its energetic and ecological consequences, whereas many students of the comparative physiology of terrestrial vertebrates have been virtually fixated on that topic. For the past 10 years, several of my students and I have exploited this situation by taking the standard questions and techniques from comparative vertebrate physiology and applying them to insects. It is surprising that this pattern of innovation is not more deliberately employed.

Call Archimedes from his buried tomb
Upon the plain of vanished Syracuse,
And feelingly the sage shall make report
How insecure, how baseless in itself,
Is the philosophy, whose sway depends
On mere material instruments—how weak
Those arts, and high inventions, if unpropped
By virtue.

Changes That Have Occurred in the Globe: When we have seen with our own eyes a mountain progressing into a plain; that is to say, an immense boulder separating from this mountain and covering the fields; an entire castle broken into pieces over the ground; a river swallowed up which then bursts out from its abyss; clear marks of a vast amount of water having once flooded regions now inhabited, and a hundred vestiges of other transformations, then we are much more willing to believe that great changes altered the face of the earth, than a Parisian lady who knows only that the place where her house was built was once a cultivated field. However, a lady from Naples who has seen the buried ruins of Herculaneum, is much less subject to the bias which leads us to believe that everything has always been as it is today.

Even for the physicist the description in plain language will be a criterion of the degree of understanding that has been reached.

For, as the element of water lies in the middle of the globe, so, the branches run out from the root in its circuit on all sides towards the plains and towards the light. From this root very many branches are born. One branch is the Rhine, another the Danube, another the Nile, etc.

I believe that the useful methods of mathematics are easily to be learned by quite young persons, just as languages are easily learned in youth. What a wondrous philosophy and history underlie the use of almost every word in every language—yet the child learns to use the word unconsciously. No doubt when such a word was first invented it was studied over and lectured upon, just as one might lecture now upon the idea of a rate, or the use of Cartesian co-ordinates, and we may depend upon it that children of the future will use the idea of the calculus, and use squared paper as readily as they now cipher. … When Egyptian and Chaldean philosophers spent years in difficult calculations, which would now be thought easy by young children, doubtless they had the same notions of the depth of their knowledge that Sir William Thomson might now have of his. How is it, then, that Thomson gained his immense knowledge in the time taken by a Chaldean philosopher to acquire a simple knowledge of arithmetic? The reason is plain. Thomson, when a child, was taught in a few years more than all that was known three thousand years ago of the properties of numbers. When it is found essential to a boy’s future that machinery should be given to his brain, it is given to him; he is taught to use it, and his bright memory makes the use of it a second nature to him; but it is not till after-life that he makes a close investigation of what there actually is in his brain which has enabled him to do so much. It is taken because the child has much faith. In after years he will accept nothing without careful consideration. The machinery given to the brain of children is getting more and more complicated as time goes on; but there is really no reason why it should not be taken in as early, and used as readily, as were the axioms of childish education in ancient Chaldea.

If you walked into Netscape headquarters with a plain old modem from CompUSA they’d think it was a garage-door opener.

In India we have clear evidence that administrative statistics had reached a high state of organization before 300 B.C. In the Arthasastra of Kautilya … the duties of the Gopa, the village accountant, [include] “by setting up boundaries to villages, by numbering plots of grounds as cultivated, uncultivated, plains, wet lands, gardens, vegetable gardens, fences (váta), forests altars, temples of gods, irrigation works, cremation grounds, feeding houses (sattra), places where water is freely supplied to travellers (prapá), places of pilgrimage, pasture grounds and roads, and thereby fixing the boundaries of various villages, of fields, of forests, and of roads, he shall register gifts, sales, charities, and remission of taxes regarding fields.”

In physics we have dealt hitherto only with periodic crystals. To a humble physicist’s mind, these are very interesting and complicated objects; they constitute one of the most fascinating and complex material structures by which inanimate nature puzzles his wits. Yet, compared with the aperiodic crystal, they are rather plain and dull. The difference in structure is of the same kind as that between an ordinary wallpaper in which the same pattern is repeated again and again in regular periodicity and a masterpiece of embroidery, say a Raphael tapestry, which shows no dull repetition, but an elaborate, coherent, meaningful design traced by the great master.

In the following pages I offer nothing more than simple facts, plain arguments, and common sense; and have no other preliminaries to settle with the reader, than that he will divest himself of prejudice and repossession, and suffer his reason and feelings to determine for themselves; and that he will put on, or rather that he will not put off, the true character of man, and generously enlarge his view beyond the present day.

In the mountains of Parma and Piacenza, multitudes of shells and corals filled with worm-holes may be seen still adhering to the rocks, and when I was making the great horse at Milan a large sack of those which had been found in these parts was brought to my workshop by some peasants... The red stone of the mountains of Verona is found with shells all intermingled, which have become part of this stone... And if you should say that these shells have been and still constantly are being created in such places as these by the nature of the locality or by potency of the heavens in these spots, such an opinion cannot exist in brains possessed of any extensive powers of reasoning because the years of their growth are numbered upon the outer coverings of their shells; and both small and large ones may be seen; and these would not have grown without feeding, or fed without movement, and here [embedded in rock] they would not have been able to move... The peaks of the Apennines once stood up in a sea, in the form of islands surrounded by salt water... and above the plains of Italy where flocks of birds are flying today, fishes were once moving in large shoals.

It is difficult to give an idea of the vast extent of modern mathematics. The word “extent” is not the right one: I mean extent crowded with beautiful detail—not an extent of mere uniformity such as an objectless plain, but of a tract of beautiful country seen at first in the distance, but which will bear to be rambled through and studied in every detail of hillside and valley, stream, rock, wood, and flower.

It seems plain and self-evident, yet it needs to be said: the isolated knowledge obtained by a group of specialists in a narrow field has in itself no value whatsoever, but only in its synthesis with all the rest of knowledge and only inasmuch as it really contributes in this synthesis toward answering the demand, ‘Who are we?’

May we attribute to the color of the herbage and plants, which no doubt clothe the plains of Mars, the characteristic hue of that planet, which is noticeable by the naked eye, and which led the ancients to personify it as a warrior?

Most people … do not know that when the white man came Honolulu was a treeless, sandy plain, with a fringe of cocoanut trees along the shore. Honolulu, as it is to-day, is the creation of the foreigner. It is his handiwork. Walk into one of the numerous yards where plants and trees and vines are growing, as though on their native soil, and you will find that every one of them has been imported within a comparatively recent period. … Here is the rubber tree, the banyan, the baobab, the litchee, the avocado, the mango, and palms innumerable.

No science doth make known the first principles whereon it buildeth; but they are always taken as plain and manifest in themselves, or as proved and granted already, some former knowledge having made them evident.

Nothing astonishes men so much as common sense and plain dealing.

Nothing will sustain you more potently than the power to recognize in your humdrum routine, as perhaps it may be thought, the true poetry of life—the poetry of the commonplace, of the ordinary man, of the plain, toil-worn woman, with their loves and their joys, their sorrows and their griefs.

Of plain, sound sense, life’s current coin is made; With that we drive the most substantial trade.

Sir, the reason is very plain; knowledge is of two kinds. We know a subject ourselves, or we know where we can find information upon it.

Standing beside each other, we feasted our eyes. Above us the cerulean sky deepened to an inky black as the remnants of the atmosphere gave way to the depths of space. The mighty Himalaya were now a sparkling relief map spread out before us and garnished with a gleaming lattice work of swirling glaciers. Even Cho Oyu, Lhotse and Makalu, all 8,000-meter giants, were dwarfed. To the east and west, Kanchenjunga and Shishapangma, two more great sentinels of the Himalaya, stood crystal clear over 100 kilometers away. To the north were the burnished plains of Tibet, and to the south the majestic peaks and lush foothills of Nepal. We stood on the crown jewel of the earth, the curved horizon spinning endlessly around us.

That hemisphere of the moon which faces us is better known than the earth itself; its vast desert plains have been surveyed to within a few acres; its mountains and craters have been measured to within a few yards; while on the earth's surface there are 30,000,000 square kilometres (sixty times the extent of France), upon which the foot of man has never trod, which the eye of man has never seen.

The function of Latin literature is its expression of Rome. When to England and France your imagination can add Rome in the background, you have laid firm the foundations of culture. The understanding of Rome leads back to the Mediterranean civilisation of which Rome was the last phase, and it automatically exhibits the geography of Europe, and the functions of seas and rivers and mountains and plains. The merit of this study in the education of youth is its concreteness, its inspiration to action, and the uniform greatness of persons, in their characters and their staging. Their aims were great, their virtues were great, and their vices were great. They had the saving merit of sinning with cart ropes.

The more I think of it, I find this conclusion more impressed upon me—that the greatest thing a human soul ever does in this world is to see something, and tell what it saw in a plain way.

The plain fact is that education is itself a form of propaganda–a deliberate scheme to outfit the pupil, not with the capacity to weigh ideas, but with a simple appetite for gulping ideas readymade. The aim is to make ‘good’ citizens, which is to say, docile and uninquisitive citizens.

The reasoning of mathematicians is founded on certain and infallible principles. Every word they use conveys a determinate idea, and by accurate definitions they excite the same ideas in the mind of the reader that were in the mind of the writer. When they have defined the terms they intend to make use of, they premise a few axioms, or self-evident principles, that every one must assent to as soon as proposed. They then take for granted certain postulates, that no one can deny them, such as, that a right line may be drawn from any given point to another, and from these plain, simple principles they have raised most astonishing speculations, and proved the extent of the human mind to be more spacious and capacious than any other science.

The rocks have a history; gray and weatherworn, they are veterans of many battles; they have most of them marched in the ranks of vast stone brigades during the ice age; they have been torn from the hills, recruited from the mountaintops, and marshaled on the plains and in the valleys; and now the elemental war is over, there they lie waging a gentle but incessant warfare with time and slowly, oh, so slowly, yielding to its attacks!

The ruthless destruction of their forests by the Chinese is one of the reasons why famine and plague today hold this nation in their sinister grasp. Denudation, wherever practiced, leaves naked soil; floods and erosion follow, and when the soil is gone men must also go—and the process does not take long. The great plains of Eastern China were centuries ago transformed from forest into agricultural land. The mountain plateau of Central China have also within a few hundred years been utterly devastated of tree growth, and no attempt made at either natural or artificial reforestation. As a result, the water rushes off the naked slopes in veritable floods, gullying away the mountain sides, causing rivers to run muddy with yellow soil, and carrying enormous masses of fertile earth to the sea. Water courses have also changed; rivers become uncontrollable, and the water level of the country is lowered perceptibly. In consequence, the unfortunate people see their crops wither and die for lack of water when it is most needed.

The simple and plain fact is that the scientific method wins its success by ignoring parts of reality as given in experience; it is perfectly right to do this for its own purposes; but it must not be permitted by a kind of bluff to create the impression that what it ignores is non-existent.

Why has not Man a microscopic eye?
For this plain reason, Man is not a Fly.

Why, then, are we surprised that comets, such a rare spectacle in the universe, are not known, when their return is at vast intervals?. … The time will come when diligent research over long periods will bring to light things which now lie hidden. A single lifetime, even though entirely devoted to the sky, would not be enough for the investigation of so vast a subject … And so this knowledge will be unfolded only through long successive ages. There will come a time when our descendants will be amazed that we did not know things that are so plain to them …. Many discoveries are reserved for ages still to come, when memory of us will have been effaced. Our universe is a sorry little affair unless it has in it something for every age to investigate … Nature does not reveal her mysteries once and for all. Someday there will be a man who will show in what regions comets have their orbit, why they travel so remote from other celestial bodies, how large they are and what sort they are.

You see layers as you look down. You see clouds towering up. You see their shadows on the sunlit plains, and you see a ship’s wake in the Indian Ocean and brush fires in Africa and a lightning storm walking its way across Australia. You see the reds and the pinks of the Australian desert, and it’s just like a stereoscopic view of all nature, except you’re a hundred ninety miles up.