[I have a great] distaste for controversy…. I have often seen it do great harm, and yet remember few cases in natural knowledge where it has helped much either to pull down error or advance truth. Criticism, on the other hand, is of much value.

[N]o scientist likes to be criticized. … But you don’t reply to critics: “Wait a minute, wait a minute; this is a really good idea. I’m very fond of it. It’s done you no harm. Please don’t attack it.” That's not the way it goes. The hard but just rule is that if the ideas don't work, you must throw them away. Don't waste any neurons on what doesn’t work. Devote those neurons to new ideas that better explain the data. Valid criticism is doing you a favor.

[The object of education is] to train the mind to ascertain the sequence of a particular conclusion from certain premises, to detect a fallacy, to correct undue generalisation, to prevent the growth of mistakes in reasoning. Everything in these must depend on the spirit and the manner in which the instruction itself is conveyed and honoured. If you teach scientific knowledge without honouring scientific knowledge as it is applied, you do more harm than good. I do think that the study of natural science is so glorious a school for the mind, that with the laws impressed on all these things by the Creator, and the wonderful unity and stability of matter, and the forces of matter, there cannot be a better school for the education of the mind.

[The parasite that causes malaria] edges through the cells of the stomach wall of the mosquito and forms a cyst which grows and eventually bursts to release hundreds of “sporozoites” into the body cavity of the mosquito … As far as we can tell, the parasite does not harm the mosquito … It has always seemed to me, though, that these growing cysts … must at least give the mosquito something corresponding to a stomach-ache.

Dogbert (advice to Boss): Every credible scientist on earth says your products harm the environment. I recommend paying weasels to write articles casting doubt on the data. Then eat the wrong kind of foods and hope you die before the earth does.

A Chinese tale tells of some men sent to harm a young girl who, upon seeing her beauty, become her protectors rather than her violators. That’s how I felt seeing the Earth for the first time. "I could not help but love and cherish her.

A free soul ought not to pursue any study slavishly; for while bodily labors performed under constraint do not harm the body, nothing that is learned under compulsion stays with the mind.

A frequent misunderstanding of my vision of Gaia is that I champion complacence, that I claim feedback will always protect the environment from any serious harm that humans might do. It is sometimes more crudely put as “Lovelock’s Gaia gives industry the green light to pollute at will.” The truth is almost diametrically opposite. Gaia, as I see her, is no doting mother tolerant of misdemeanors, nor is she some fragile and delicate damsel in danger from brutal mankind. She is stern and tough, always keeping the world warm and comfortable for those who obey the rules, but ruthless in her destruction of those who transgress. Her unconscious goal is a planet fit for life. If humans stand in the way of this, we shall be eliminated with as little pity as would be shown by the micro-brain of an intercontinental ballistic nuclear missile in full flight to its target.

An ever-green revolution implies the enhancement of productivity in perpetuity without associated ecological harm.

An infinity of these tiny animals defoliate our plants, our trees, our fruits... they attack our houses, our fabrics, our furniture, our clothing, our furs ... He who in studying all the different species of insects that are injurious to us, would seek means of preventing them from harming us, would seek to cause them to perish, proposes for his goal important tasks indeed.

Apprehension, uncertainty, waiting, expectation, fear of surprise, do a patient more harm than any exertion. Remember he is face to face with his enemy all the time.

As to diseases, make a habit of two things—to help, or at least to do no harm.

At first men try with magic charms
To fertilize the earth,
To keep their flocks and herds from harm
And bring new young to birth.

Then to capricious gods they turn
To save from fire or flood;
Their smoking sacrifices burn
On altars red with blood.

Next bold philosopher and sage
A settled plan decree
And prove by thought or sacred page
What Nature ought to be.

But Nature smiles—a Sphinx-like smile
Watching their little day
She waits in patience for a while—
Their plans dissolve away.

Then come those humbler men of heart
With no completed scheme,
Content to play a modest part,
To test, observe, and dream.

Till out of chaos come in sight
Clear fragments of a Whole;
Man, learning Nature’s ways aright
Obeying, can control.

Committees are dangerous things that need most careful watching. I believe that a research committee can do one useful thing and one only. It can find the workers best fitted to attack a particular problem, bring them together, give them the facilities they need, and leave them to get on with the work. It can review progress from time to time, and make adjustments; but if it tries to do more, it will do harm.

During the eight days I spent in space, I realized that mankind needs height primarily to better know our long-suffering Earth, to see what cannot be seen close up. Not just to love her beauty, but also to ensure that we do not bring even the slightest harm to the natural world

Each generation has its few great mathematicians, and mathematics would not even notice the absence of the others. They are useful as teachers, and their research harms no one, but it is of no importance at all. A mathematician is great or he is nothing.

Exercises in being obedient can not begin too early, and I have, during an almost daily observation of six years, discovered no harm from an early, consistent guiding of the germinating will, provided only this guiding be done with the greatest mildness and justice, as if the infant had already an insight into the benefits of obedience.

I suppose that the first chemists seemed to be very hard-hearted and unpoetical persons when they scouted the glorious dream of the alchemists that there must be some process for turning base metals into gold. I suppose that the men who first said, in plain, cold assertion, there is no fountain of eternal youth, seemed to be the most cruel and cold-hearted adversaries of human happiness. I know that the economists who say that if we could transmute lead into gold, it would certainly do us no good and might do great harm, are still regarded as unworthy of belief. Do not the money articles of the newspapers yet ring with the doctrine that we are getting rich when we give cotton and wheat for gold rather than when we give cotton and wheat for iron?

Is pure science to be considered as something potentially harmful? Answer: Most certainly! Every child knows that it is potentially exceedingly harmful. … The menace of blowing ourselves up by atom bombs, doing ourselves in by chemical or biological warfare, or by population explosion, is certainly with us. I consider the environment thing a trivial question, by comparison—like housekeeping. In any home, the dishes have to be washed, the floors swept, the beds made, and there must be rules as to who is allowed to produce how much stink and noise, and where in the house: When the garbage piles up, these questions become pressing. But they are momentary problems. Once the house is in order, you still want to live in it, not just sit around enjoying its orderliness. I would be sorry to see Caltech move heavily into this type of applied research. … SCIENCE POTENTIALLY HARMFUL? DEFINITELY.

It is certain that as a nation we are all smoking a great deal too much ... Smoking among boys—to whom it cannot possibly do any kind of good, while it may do a vast amount of active harm—is becoming prevalent to a most pernicious extent. ... It would be an excellent thing for the morality of the people could the use of “intoxicants and tobacco” be forbidden to all persons under twenty years of age. (1878)

It may seem a strange principle to enunciate as the very first requirement in a Hospital that it should do the sick no harm.

Knowing, henceforth, the physiognomy of the disease when allowed to run its own course, you can, without risk of error, estimate the value of the different medications which have been employed. You will discover which remedies have done no harm, and which have notably curtailed the duration of the disease; and thus for the future you will have a standard by which to measure the value of the medicine which you see employed to counteract the malady in question. What you have done in respect of one disease, you will be able to do in respect of many; and by proceeding in this way you will be able, on sure data, to pass judgment on the treatment pursued by your masters.

Most American homes have alternating current, which means that the electricty goes in one direction for a while, then goes in the other direction. This prevents harmful electron buildup in the wires.

On the whole, more harm than good is done by medication.

Poets say science takes away from the beauty of the stars—mere globs of gas atoms. Nothing is “mere.” I too can see the stars on a desert night, and feel them. But do I see less or more? The vastness of the heavens stretches my imagination—stuck on this carousel my little eye can catch one-million-year-old light. A vast pattern—of which I am a part. … What is the pattern, or the meaning, or the “why?” It does not do harm to the mystery to know a little about it. For far more marvelous is the truth than any artists of the past imagined it. Why do the poets of the present not speak of it? What men are poets who can speak of Jupiter if he were a man, but if he is an immense spinning sphere of methane and ammonia must be silent?

Science helps us before all things in this, that it somewhat lightens the feeling of wonder with which Nature fills us; then, however, as life becomes more and more complex, it creates new facilities for the avoidance of what would do us harm and the promotion of what will do us good.

Science in the service of humanity is technology, but lack of wisdom may make the service harmful.

Science is not ... a perfect instrument, but it is a superb and invaluable tool that works harm only when taken as an end in itself.

Science is the search for truth. It is not a game in which one tries to beat his opponent, to do harm to others. We need to have the spirit of science in international affairs, to make the conduct of international affairs the effort to find the right solution, the just solution of international problems, not the effort by each nation to get the better of other nations, to do harm to them when it is possible.

Sometimes I wonder whether there is any such thing as biology. The word was invented rather late—in 1809—and other words like botany, zoology, physiology, anatomy, have much longer histories and in general cover more coherent and unified subject matters. … I would like to see the words removed from dictionaries and college catalogues. I think they do more harm than good because they separate things that should not be separated…

The alternating current will kill people, of course. So will gunpowder, and dynamite, and whisky, and lots of other things; but we have a system whereby the deadly electricity of the alternating current can do no harm unless a man is fool enough to swallow a whole dynamo.

The ancients devoted a lifetime to the study of arithmetic; it required days to extract a square root or to multiply two numbers together. Is there any harm in skipping all that, in letting the school boy learn multiplication sums, and in starting his more abstract reasoning at a more advanced point? Where would be the harm in letting the boy assume the truth of many propositions of the first four books of Euclid, letting him assume their truth partly by faith, partly by trial? Giving him the whole fifth book of Euclid by simple algebra? Letting him assume the sixth as axiomatic? Letting him, in fact, begin his severer studies where he is now in the habit of leaving off? We do much less orthodox things. Every here and there in one’s mathematical studies one makes exceedingly large assumptions, because the methodical study would be ridiculous even in the eyes of the most pedantic of teachers. I can imagine a whole year devoted to the philosophical study of many things that a student now takes in his stride without trouble. The present method of training the mind of a mathematical teacher causes it to strain at gnats and to swallow camels. Such gnats are most of the propositions of the sixth book of Euclid; propositions generally about incommensurables; the use of arithmetic in geometry; the parallelogram of forces, etc., decimals.

The conception that antibodies, which should protect against disease, are also responsible for the disease, sounds at first absurd. This has as its basis the fact that we are accustomed to see in disease only the harm done to the organism and to see in the antibodies solely antitoxic [protective] substances. One forgets too easily that the disease represents only a stage in the development of immunity, and that the organism often attains the advantage of immunity only by means of disease. ... Serum sickness represents, so to speak, an unnatural (artificial) form of disease.

The development doctrines are doing much harm on both sides of the Atlantic, especially among intelligent mechanics, and a class of young men engaged in the subordinate departments of trade and the law. And the harm thus considerable in amount must be necessarily more than considerable in degree. For it invariably happens, that when persons in these walks become materialists, they become turbulent subjects and bad men.

The science of legislation, is like that of medicine; in one respect, that it is far more easy to point out what will do harm, than what will do good.

The theory of numbers is particularly liable to the accusation that some of its problems are the wrong sort of questions to ask. I do not myself think the danger is serious; either a reasonable amount of concentration leads to new ideas or methods of obvious interest, or else one just leaves the problem alone. “Perfect numbers” certainly never did any good, but then they never did any particular harm.

The value the world sets upon motives is often grossly unjust and inaccurate. Consider, for example, two of them: mere insatiable curiosity and the desire to do good. The latter is put high above the former, and yet it is the former that moves some of the greatest men the human race has yet produced: the scientific investigators. What animates a great pathologist? Is it the desire to cure disease, to save life? Surely not, save perhaps as an afterthought. He is too intelligent, deep down in his soul, to see anything praiseworthy in such a desire. He knows by life-long observation that his discoveries will do quite as much harm as good, that a thousand scoundrels will profit to every honest man, that the folks who most deserve to be saved will probably be the last to be saved. No man of self-respect could devote himself to pathology on such terms. What actually moves him is his unquenchable curiosity–his boundless, almost pathological thirst to penetrate the unknown, to uncover the secret, to find out what has not been found out before. His prototype is not the liberator releasing slaves, the good Samaritan lifting up the fallen, but the dog sniffing tremendously at an infinite series of rat-holes.

There is no great harm in the theorist who makes up a new theory to fit a new event. But the theorist who starts with a false theory and then sees everything as making it come true is the most dangerous enemy of human reason.

Undeveloped though the science [of chemistry] is, it already has great power to bring benefits. Those accruing to physical welfare are readily recognized, as in providing cures, improving the materials needed for everyday living, moving to ameliorate the harm which mankind by its sheer numbers does to the environment, to say nothing of that which even today attends industrial development. And as we continue to improve our understanding of the basic science on which applications increasingly depend, material benefits of this and other kinds are secured for the future.

We have to stop thinking of human needs and rights alone. Let us be brave and see that the real threat comes from the living earth, which we have harmed and is now at war with us.

What animates a great pathologist? Is it the desire to cure disease, to save life? Surely not, save perhaps as an afterthought. He is too intelligent, deep in his soul, to see anything praiseworthy in such a desire. He knows from life-long observation that his discoveries will do quite as much harm as good, that a thousand scoundrels will profit to every honest man, that the folks who most deserve to be saved will probably be the last to be saved. ... What actually moves him is his unquenchable curiosity—his boundless, almost pathological thirst to penetrate the unknown, to uncover the secret, to find out what has not been found out before. ... [like] the dog sniffing tremendously at an infinite series of rat-holes. ... And yet he stands in the very front rank of the race

When I first ventured into the Gulf of Mexico in the 1950s, the sea appeared to be a blue infinity too large, too wild to be harmed by anything that people could do. I explored powder white beaches, dense marshes, mangrove forests, and miles of sea grass meadows alive with pink sea urchins, tiny shrimps, and seahorses half the size of my little finger. … Then, in mere decades, not millennia, the blue wilderness of my childhood disappeared: biologic change in the space of a lifetime.

You have heard of the new chemical nomenclature endeavored to be introduced by Lavoisier, Fourcroy, &c. Other chemists of this country, of equal note, reject it, and prove in my opinion that it is premature, insufficient and false. These latter are joined by the British chemists; and upon the whole, I think the new nomenclature will be rejected, after doing more harm than good. There are some good publications in it, which must be translated into the ordinary chemical language before they will be useful.