[Joseph Rotblat] was a towering figure in the search for peace in the world, who dedicated his life to trying to rid the world of nuclear weapons, and ultimately to rid the world of war itself.

[O]ur long-term security is threatened by a problem at least as dangerous as chemical, nuclear or biological weapons, or indeed international terrorism: human-induced climate change. … The impacts of global warming are such that I have no hesitation in describing it as a “weapon of mass destruction.” Like terrorism, this weapon knows no boundaries. It can strike anywhere, in any form…

Air Chief Marshal Harris [objecting to a change in strategy recommended by statisticians]: Are we fighting this war with weapons or the slide rule?
Churchill [after puffing on his cigar]: That's a good idea. Let's try the slide rule.

A fear of intellectual inadequacy, of powerlessness before the tireless electronic wizards, has given rise to dozens of science-fiction fantasies of computer takeovers. ... Other scientists too are apprehensive. D. Raj Reddy, a computer scientist at Pittsburgh’s Carnegie-Mellon University, fears that universally available microcomputers could turn into formidable weapons. Among other things, says Reddy, sophisticated computers in the wrong hands could begin subverting a society by tampering with people’s relationships with their own computers—instructing the other computers to cut off telephone, bank and other services, for example.

A first step in the study of civilization is to dissect it into details, and to classify these in their proper groups. Thus, in examining weapons, they are to be classed under spear, club, sling, bow and arrow, and so forth; among textile arts are to be ranged matting, netting, and several grades of making and weaving threads; myths are divided under such headings as myths of sunrise and sunset, eclipse-myths, earthquake-myths, local myths which account for the names of places by some fanciful tale, eponymic myths which account for the parentage of a tribe by turning its name into the name of an imaginary ancestor; under rites and ceremonies occur such practices as the various kinds of sacrifice to the ghosts of the dead and to other spiritual beings, the turning to the east in worship, the purification of ceremonial or moral uncleanness by means of water or fire. Such are a few miscellaneous examples from a list of hundreds … To the ethnographer, the bow and arrow is the species, the habit of flattening children’s skulls is a species, the practice of reckoning numbers by tens is a species. The geographical distribution of these things, and their transmission from region to region, have to be studied as the naturalist studies the geography of his botanical and zoological species.

A humanitarian is a man who believes that no human being should be sacrificed to a project—especially to the project of perfecting nuclear weapons to kill hundreds of millions of people.

As the Director of the Theoretical Division of Los Alamos, I participated at the most senior level in the World War II Manhattan Project that produced the first atomic weapons.
Now, at age 88, I am one of the few remaining such senior persons alive. Looking back at the half century since that time, I feel the most intense relief that these weapons have not been used since World War II, mixed with the horror that tens of thousands of such weapons have been built since that time—one hundred times more than any of us at Los Alamos could ever have imagined.
Today we are rightly in an era of disarmament and dismantlement of nuclear weapons. But in some countries nuclear weapons development still continues. Whether and when the various Nations of the World can agree to stop this is uncertain. But individual scientists can still influence this process by withholding their skills.
Accordingly, I call on all scientists in all countries to cease and desist from work creating, developing, improving and manufacturing further nuclear weapons - and, for that matter, other weapons of potential mass destruction such as chemical and biological weapons.
[On the occasion of the 50th Anniversary of Hiroshima.]

Bismarck, enraged at Virchow’s constant criticisms, has his seconds call upon the scientist to challenge him to a duel. “As the challenged party, I have the choice of weapons,” said Virchow, “and I chose these.” He held aloft two sausages. “One of these,” he went on, “is infected with deadly germs; the other is perfectly sound. Let his Excellency decide which one he wishes to eat, and I will eat the other.” Almost immediately the message came back that the chancellor had decided to laugh off the duel.

Certainly, speaking for the United States of America, I pledge that, as we sign this treaty in an era of negotiation, we consider it only one step toward a greater goal: the control of nuclear weapons on earth and the reduction of the danger that hangs over all nations as long as those weapons are not controlled.

Deprived, therefore, as regards this period, of any assistance from history, but relieved at the same time from the embarrassing interference of tradition, the archaeologist is free to follow the methods which have been so successfully pursued in geology—the rude bone and stone implements of bygone ages being to the one what the remains of extinct animals are to the other. The analogy may be pursued even further than this. Many mammalia which are extinct in Europe have representatives still living in other countries. Our fossil pachyderms, for instance, would be almost unintelligible but for the species which still inhabit some parts of Asia and Africa; the secondary marsupials are illustrated by their existing representatives in Australia and South America; and in the same manner, if we wish clearly to understand the antiquities of Europe, we must compare them with the rude implements and weapons still, or until lately, used by the savage races in other parts of the world. In fact, the Van Diemaner and South American are to the antiquary what the opossum and the sloth are to the geologist.

Despite the dazzling successes of modern technology and the unprecedented power of modern military systems, they suffer from a common and catastrophic fault. While providing us with a bountiful supply of food, with great industrial plants, with high-speed transportation, and with military weapons of unprecedented power, they threaten our very survival.

Despite the vision and the far-seeing wisdom of our wartime heads of state, the physicists felt a peculiarly intimate responsibility for suggesting, for supporting, and in the end, in large measure, for achieving the realization of atomic weapons. Nor can we forget that these weapons, as they were in fact used, dramatized so mercilessly the inhumanity and evil of modern war. In some sort of crude sense which no vulgarity, no humor, no overstatement can quite extinguish, the physicists have known sin; and this is a knowledge which they cannot lose.

Every inhabitant of this planet must contemplate the day when this planet may no longer be habitable. Every man, woman and child lives under a nuclear sword of Damocles, hanging by the slenderest of threads, capable of being cut at any moment by accident or miscalculation or by madness. The weapons of war must be abolished before they abolish us.

Fleets are not confined to the ocean, but now sail over the land. … All the power of the British Navy has not been able to prevent Zeppelins from reaching England and attacking London, the very heart of the British Empire. Navies do not protect against aerial attack. … Heavier-than-air flying machines of the aeroplane type have crossed right over the heads of armies, of million of men, armed with the most modern weapons of destruction, and have raided places in the rear. Armies do not protect against aerial war.

I call upon the scientific community in our country, those who gave us nuclear weapons, to turn their great talents now to the cause of mankind and world peace, to give us the means of rendering those nuclear weapons impotent and obsolete.
About his proposed Strategic Defense Initiative, later to be known as 'Star Wars.')

I got a four year scholarship to Harvard, and while I was there they wanted to groom me for work in the Star Wars program designing weapons ignited by hydrogen bombs. I didn't want to do that. I thought about how many scientists had died in World War II.

I have no doubt that we will be successful in harnessing the sun's energy. … If sunbeams were weapons of war, we would have had solar energy centuries ago.

I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones.

I never pick up an item without thinking of how I might improve it. I never perfected an invention that I did not think about in terms of the service it might give others. I want to save and advance human life, not destroy it. I am proud of the fact that I never invented weapons to kill. The dove is my emblem.

I stood there with only the weapons and the powers that Nature had endowed me with – hands, feet, and teeth.

I’m not going to fight in the physical with physical weapons, because it’s not a physical fight. I’m going to fight with spiritual weapons, cause it’s a spiritual fight.

If atomic bombs are to be added as new weapons to the arsenals of a warring world, or to the arsenals of nations preparing for war, then the time will come when mankind will curse the names of Los Alamos and Hiroshima. The people must unite, or they will perish.

If the militarily most powerful—and least threatened—states need nuclear weapons for their security, how can one deny such security to countries that are truly insecure? The present nuclear policy is a recipe for proliferation. It is a policy for disaster.

Imagine a room awash in gasoline, and there are two implacable enemies in that room. One of them has nine thousand matches. The other has seven thousand matches. Each of them is concerned about who's ahead, who's stronger. Well that's the kind of situation we are actually in. The amount of weapons that are available to the United States and the Soviet Union are so bloated, so grossly in excess of what's needed to dissuade the other, that if it weren't so tragic, it would be laughable. What is necessary is to reduce the matches and to clean up the gasoline.

In the arts of life main invents nothing; but in the arts of death he outdoes Nature herself, and produces by chemistry and machinery all the slaughter of plague, pestilence and famine. … There is nothing in Man's industrial machinery but his greed and sloth: his heart is in his weapons.

It did not take atomic weapons to make man want peace. But the atomic bomb was the turn of the screw. The atomic bomb made the prospect of future war unendurable. It has led us up those last few steps to the mountain pass; and beyond there is a different country.

It is by the aid of iron that we construct houses, cleave rocks, and perform so many other useful offices of life. But it is with iron also that wars, murders, and robberies are effected, and this, not only hand to hand, but from a distance even, by the aid of missiles and winged weapons, now launched from engines, now hurled by the human arm, and now furnished with feathery wings. This last I regard as the most criminal artifice that has been devised by the human mind; for, as if to bring death upon man with still greater rapidity, we have given wings to iron and taught it to fly. ... Nature, in conformity with her usual benevolence, has limited the power of iron, by inflicting upon it the punishment of rust; and has thus displayed her usual foresight in rendering nothing in existence more perishable, than the substance which brings the greatest dangers upon perishable mortality.

It is hard to think of fissionable materials when fashioned into bombs as being a source of happiness. However this may be, if with such destructive weapons men are to survive, they must grow rapidly in human greatness. A new level of human understanding is needed. The reward for using the atom’s power towards man’s welfare is great and sure. The punishment for its misuse would seem to be death and the destruction of the civilization that has been growing for a thousand years. These are the alternatives that atomic power, as the steel of Daedalus, presents to mankind. We are forced to grow to greater manhood.

It may be that ... when the advance of destructive weapons enables everyone to kill everybody else nobody will want to kill anyone at all. [Referring to the hydrogen bomb.]

Natural science is one of man’s weapons in his fight for freedom. For the purpose of attaining freedom in the world of nature, man must use natural science to understand, conquer, and change nature and thus attain freedom from nature.

Nobody since Newton has been able to use geometrical methods to the same extent for the like purposes; and as we read the Principia we feel as when we are in an ancient armoury where the weapons are of gigantic size; and as we look at them we marvel what manner of man he was who could use as a weapon what we can scarcely lift as a burthen.

Nuclear weapons offer us nothing but a balance of terror, and a balance of terror is still terror.

On May 15, 1957 Linus Pauling made an extraordinary speech to the students of Washington University. ... It was at this time that the idea of the scientists' petition against nuclear weapons tests was born. That evening we discussed it at length after dinner at my house and various ones of those present were scribbling and suggesting paragraphs. But it was Linus Pauling himself who contributed the simple prose of the petition that was much superior to any of the suggestions we were making.

Reductio ad absurdum, which Euclid loved so much, is one of a mathematician's finest weapons. It is a far finer gambit than any chess play: a chess player may offer the sacrifice of a pawn or even a piece, but a mathematician offers the game.

Science is dangerous. There is no question but that poison gas, genetic engineering, and nuclear weapons and power stations are terrifying. It may be that civilization is falling apart and the world we know is coming to an end. In that case, why no turn to religion and look forward to the Day of Judgment, ... [being] lifted into eternal bliss ... [and] watching the scoffers and disbelievers writhe forever in torment.

Science is one of our best weapons against authoritarianism, but authoritarianism has been known to surface among scientists. When this happens, misguided perfectionists or romanticists sometimes seek to root it out by attacking science. Instead of destroying science, which would merely return us to ignorance and superstition, what we need to do is to expose and root out the authoritarians.

Scientific subjects do not progress necessarily on the lines of direct usefulness. Very many applications of the theories of pure mathematics have come many years, sometimes centuries, after the actual discoveries themselves. The weapons were at hand, but the men were not able to use them.

Structures are the weapons of the mathematician.

The eyes of the world now look into space, to the moon and to the planets beyond, and we have vowed that we shall not see it governed by a hostile flag of conquest, but by a banner of freedom and peace. We have vowed that we shall not see space filled with weapons of mass destruction, but with instruments of knowledge and understanding.

The first man of science was he who looked into a thing, not to learn whether it furnished him with food, or shelter, or weapons, or tools, armaments, or playwiths but who sought to know it for the gratification of knowing.

The last few centuries have seen the world freed from several scourges—slavery, for example; death by torture for heretics; and, most recently, smallpox. I am optimistic enough to believe that the next scourge to disappear will be large-scale warfare—killed by the existence and nonuse of nuclear weapons.

The marriage of reason and nightmare which has dominated the 20th century has given birth to an ever more ambiguous world. Across the communications landscape move the specters of sinister technologies and the dreams that money can buy. Thermonuclear weapons systems and soft drink commercials coexist in an overlit realm ruled by advertising and pseudoevents, science and pornography. Over our lives preside the great twin leitmotifs of the 20th century—sex and paranoia.

The mere existence of nuclear weapons by the thousands is an incontrovertible sign of human insanity.

The more innocuous the name of a weapon, the more hideous its impact. (Some of the most horrific weapons of the Vietnam era were named “Bambi”, “Infant”, “Daisycutter”, “Grasshopper”, and “Agent Orange.” Nor is the trend new: from the past we have “Mustard Gas”, “Angel Chasers” (two cannonballs linked with a chain for added destruction) and “The Peacemaker” to name but a few.)

The position in which we are now is a very strange one which in general political life never happened. Namely, the thing that I refer to is this: To have security against atomic bombs and against the other biological weapons, we have to prevent war, for if we cannot prevent war every nation will use every means that is at their disposal; and in spite of all promises they make, they will do it.

The science of weapons and war has made us all one world and one human race with one common destiny.

The simple rule about weapons is that if thery can be built, they will be built.

The situation with regard to insulin is particularly clear. In many parts of the world diabetic children still die from lack of this hormone. ... [T]hose of us who search for new biological facts and for new and better therapeutic weapons should appreciate that one of the central problems of the world is the more equitable distribution and use of the medical and nutritional advances which have already been established. The observations which I have recently made in parts of Africa and South America have brought this fact very forcible to my attention.

The sole precoccupation of this learned society was the destruction of humanity for philanthropic reasons and the perfection of weapons as instruments of civilization.

The study of mathematics is apt to commence in disappointment. … We are told that by its aid the stars are weighed and the billions of molecules in a drop of water are counted. Yet, like the ghost of Hamlet's father, this greatest science eludes the efforts of our mental weapons to grasp it.

The study of mathematics is apt to commence in disappointment. The important applications of the science, the theoretical interest of its ideas, and the logical rigour of its methods all generate the expectation of a speedy introduction to processes of interest. We are told that by its aid the stars are weighed and the billions of molecules in a drop of water are counted. Yet, like the ghost of Hamlet's father, this great science eludes the efforts of our mental weapons to grasp it.

There is no such thing as a good nuclear weapons system. There is no way to achieve, in the sound sense, national security through nuclear weapons.

We are in the grip of a scientific materialism, caught in a vicious cycle where our security today seems to depend on regimentation and weapons which will ruin us tomorrow.

We are told that “Mathematics is that study which knows nothing of observation, nothing of experiment, nothing of induction, nothing of causation.” I think no statement could have been made more opposite to the facts of the case; that mathematical analysis is constantly invoking the aid of new principles, new ideas, and new methods, not capable of being defined by any form of words, but springing direct from the inherent powers and activities of the human mind, and from continually renewed introspection of that inner world of thought of which the phenomena are as varied and require as close attention to discern as those of the outer physical world (to which the inner one in each individual man may, I think, be conceived to stand somewhat in the same relation of correspondence as a shadow to the object from which it is projected, or as the hollow palm of one hand to the closed fist which it grasps of the other), that it is unceasingly calling forth the faculties of observation and comparison, that one of its principal weapons is induction, that it has frequent recourse to experimental trial and verification, and that it affords a boundless scope for the exercise of the highest efforts of the imagination and invention.

We have also here an acting cause to account for that balance so often observed in nature,—a deficiency in one set of organs always being compensated by an increased development of some others—powerful wings accompanying weak feet, or great velocity making up for the absence of defensive weapons; for it has been shown that all varieties in which an unbalanced deficiency occurred could not long continue their existen The action of this principle is exactly like that of the centrifugal governor of the steam engine, which checks and corrects any irregularities almost before they become evident; and in like manner no unbalanced deficiency in the animal kingdom can ever reach any conspicuous magnitude, because it would make itself felt at the very first step, by rendering existence difficult and extinction almost sure soon to follow.

We scientists, whose tragic destiny it has been to help make the methods of annihilation ever more gruesome and more effective, must consider it our solemn and transcendent duty to do all in our power to prevent these weapons from being used for the brutal purpose for which they were invented.

Why the dinosaurs died out is not known, but it is supposed to be because they had minute brains and devoted themselves to the growth of weapons of offense in the shape of numerous horns. However that may be, it was not through their line that life developed.