By God’s mercy British and American science outpaced all German efforts. … This revelation of the secrets of nature, long mercifully withheld from man, should arouse the most solemn reflections in the mind and conscience of every human being capable of comprehension. We must indeed pray that these awful agencies will be made to conduce to peace among the nations, and that instead of wreaking measureless havoc upon the entire globe, may become a perennial fountain of world prosperity.
[Concerning use of the atomic bomb.]

Imagine the chaos that would arise if time machines were as common as automobiles, with tens of millions of them commercially available. Havoc would soon break loose, tearing at the fabric of our universe. Millions of people would go back in time to meddle with their own past and the past of others, rewriting history in the process. … It would thus be impossible to take a simple census to see how many people there were at any given time.

It were indeed to be wish’d that our art had been less ingenious, in contriving means destructive to mankind; we mean those instruments of war, which were unknown to the ancients, and have made such havoc among the moderns. But as men have always been bent on seeking each other’s destruction by continual wars; and as force, when brought against us, can only be repelled by force; the chief support of war, must, after money, be now sought in chemistry.

Knowledge is like a knife. In the hands of a well-balanced adult it is an instrument for good of inestimable value; but in the hands of a child, an idiot, a criminal, a drunkard or an insane man, it may cause havoc, misery, suffering and crime. Science and religion have this in common, that their noble aims, their power for good, have often, with wrong men, deteriorated into a boomerang to the human race.

My dear nephew was only in his sixth year when I came to be detached from the family circle. But this did not hinder John and I from remaining the most affectionate friends, and many a half or whole holiday he was allowed to spend with me, was dedicated to making experiments in chemistry, where generally all boxes, tops of tea-canisters, pepper-boxes, teacups, &c., served for the necessary vessels, and the sand-tub furnished the matter to be analysed. I only had to take care to exclude water, which would have produced havoc on my carpet.

The oppressive weight of disaster and tragedy in our lives does not arise from a high percentage of evil among the summed total of all acts, but from the extraordinary power of exceedingly rare incidents of depravity to inflict catastrophic damage, especially in our technological age when airplanes can become powerful bombs. (An even more evil man, armed only with a longbow, could not have wreaked such havoc at the Battle of Agincourt in 1415.)

The Unexpected stalks a farm in big boots like a vagrant bent on havoc. Not every farmer is an inventor, but the good ones have the seeds of invention within them. Economy and efficiency move their relentless tinkering and yet the real motive often seems to be aesthetic. The mind that first designed a cutter bar is not far different from a mind that can take the intractable steel of an outsized sickle blade and make it hum in the end. The question is how to reduce the simplicity that constitutes a problem (“It's simple; it’s broke.”) to the greater simplicity that constitutes a solution.