The spread of civilisation may be likened to a fire; first, a feeble spark, next a flickering flame, then a mighty blaze, ever increasing in speed and power.

Our virtues and our failings are inseparable, like force and matter. When they separate, man is no more.

Let the future tell the truth, and evaluate each one according to his work and accomplishments. The present is theirs; the future, for which I have really worked, is mine.

Today's scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality.

I do not think there is any thrill that can go through the human heart like that felt by the inventor as he sees some creation of the brain unfolding to success... such emotions make a man forget food, sleep, friends, love, everything.

The spread of civilisation may be likened to a fire; first, a feeble spark, next a flickering flame, then a mighty blaze, ever increasing in speed and power.

The scientists of today think deeply instead of clearly. One must be sane to think clearly, but one can think deeply and be quite insane.

All knowledge or form conception is evoked through the medium of the eye, either in response to disturbances directly received on the retina or to their fainter secondary effects and reverberations. Other sense organs can only call forth feelings which have no reality of existence and of which no conception can be formed.

Archimedes was my ideal. I admired the works of artists, but to my mind, they were only shadows and semblances. The inventor, I thought, gives to the world creations which are palpable, which live and work.

Every living being is an engine geared to the wheelwork of the universe. Though seemingly affected only by its immediate surrounding, the sphere of external influence extends to infinite distance.

From my childhood I had been intended for the clergy. This prospect hung like a dark cloud on my mind.

I do not think you can name many great inventions that have been made by married men.

I myself eschew all stimulants. I also practically abstain from meat.

If we want to reduce poverty and misery, if we want to give to every deserving individual what is needed for a safe existence of an intelligent being, we want to provide more machinery, more power. Power is our mainstay, the primary source of our many-sided energies.

In the twenty-first century, the robot will take the place which slave labor occupied in ancient civilization.

It is paradoxical, yet true, to say, that the more we know, the more ignorant we become in the absolute sense, for it is only through enlightenment that we become conscious of our limitations. Precisely one of the most gratifying results of intellectual evolution is the continuous opening up of new and greater prospects.

Modern science says: 'The sun is the past, the earth is the present, the moon is the future.' From an incandescent mass we have originated, and into a frozen mass we shall turn. Merciless is the law of nature, and rapidly and irresistibly we are drawn to our doom.

Of the various branches of electrical investigation, perhaps the most interesting and immediately the most promising is that dealing with alternating currents.

The earth is bountiful, and where her bounty fails, nitrogen drawn from the air will refertilize her womb. I developed a process for this purpose in 1900. It was perfected fourteen years later under the stress of war by German chemists.

The feeling is constantly growing on me that I had been the first to hear the greeting of one planet to another.

The history of science shows that theories are perishable. With every new truth that is revealed we get a better understanding of Nature and our conceptions and views are modified.

The trend of opinion among eugenists is that we must make marriage more difficult. Certainly no one who is not a desirable parent should be permitted to produce progeny.

The year 2100 will see eugenics universally established. In past ages, the law governing the survival of the fittest roughly weeded out the less desirable strains. Then man's new sense of pity began to interfere with the ruthless workings of nature. As a result, we continue to keep alive and to breed the unfit.

There is no conflict between the ideal of religion and the ideal of science, but science is opposed to theological dogmas because science is founded on fact. To me, the universe is simply a great machine which never came into being and never will end. The human being is no exception to the natural order. Man, like the universe, is a machine.

There is no memory or retentive faculty based on lasting impression. What we designate as memory is but increased responsiveness to repeated stimuli.

We have soon to have everywhere smoke annihilators, dust absorbers, ozonizers, sterilizers of water, air, food and clothing, and accident preventers on streets, elevated roads and in subways. It will become next to impossible to contract disease germs or get hurt in the city, and country folk will got to town to rest and get well.

When a coil is operated with currents of very high frequency, beautiful brush effects may be produced, even if the coil be of comparatively small dimensions. The experimenter may vary them in many ways, and, if it were nothing else, they afford a pleasing sight.

With ideas it is like with dizzy heights you climb: At first they cause you discomfort and you are anxious to get down, distrustful of your own powers; but soon the remoteness of the turmoil of life and the inspiring influence of the altitude calm your blood; your step gets firm and sure and you begin to look - for dizzier heights.

Anti-social behavior is a trait of intelligence in a world full of conformists.

Every living being is an engine geared to the wheelwork of the universe. Though seemingly affected only by its immediate surrounding the sphere of external influence extends to infinite distance.

Let the future tell the truth and evaluate each one according to his work and accomplishments. The present is theirs the future for which I have really worked is mine.

The day science begins to study non-physical phenomena, it will make more progress in one decade than in all the previous centuries of its existence.

The progressive development of man is vitally dependent on invention. It is the most important product of his creative brain.

The mind is sharper and keener in seclusion and uninterrupted solitude. Originality thrives in seclusion free of outside influences beating upon us to cripple the creative mind. Be alone "that is the secret of invention: be alone, that is when ideas are born.

I am not authorized to fire substitute teachers.

Removing substantial fuel loads from our forests helps prevent catastrophic fire and better protects species, watersheds and neighboring communities that call them home.

A thought often makes us hotter than a fire.

Envy like fire always makes for the highest points.

A leaf fluttered in through the window this morning, as if supported by the rays of the sun, a bird settled on the fire escape, joy in the task of coffee, joy accompanied me as I walked.

From each one of them rose separate columns of smoke, meeting in a pall overhead, and through the smoke came stabbing flashes of fire as German shells burst with thudding shocks of sound. This was the front line of battle.

Not too much, though there's a certain amount of rancour and bitterness when someone tries to fire you.

I was at this casino minding my own business, and this guy came up to me and said, "You're gonna have to move, you're blocking a fire exit." As though if there was a fire, I wasn't gonna run. If you're flammible and have legs, you are never blocking a fire exit.

In all feats of fire-eating it should be noted that the head is thrown well back, so that the flame may pass out of the open mouth instead of up into the roof, as it would if the head were held naturally.

Wise anger is like fire from a flint: there is great ado to get it out; and when it does come, it is out again immediately.

The bourgeois prefers comfort to pleasure, convenience to liberty, and a pleasant temperature to the deathly inner consuming fire.

The best training is to play by ear: trial by fire.

Being thrown into the fire and getting the thing turned around in a hurry made it more difficult. Things have been done the hard way. I think you learn better when things are done the hard way.

Under pressure, people admit to murder, setting fire to the village church or robbing a bank, but never to being bores.

Man is a fire-stealing animal, and we can't help building machines and machine intelligences, even if, from time to time, we use them not only to outsmart ourselves but to bring us right up to the doorstep of Doom.