Science, my boy, is made up of mistakes, but they are mistakes which it is useful to make, because they lead little by little to the truth.
How many persons condemned to the horrors of solitary confinement have gone mad - simply because the thinking faculties have lain dormant!
Man's constitution is so peculiar that his health is purely a negative matter. No sooner is the rage of hunger appeased than it becomes difficult to comprehend the meaning of starvation. It is only when you suffer that you really understand.
When one has taken root, one puts out branches.
Everything great in science and art is simple. What can be less complicated than the greatest discoveries of humanity - gravitation, the compass, the printing press, the steam engine, the electric telegraph?
With happiness as with health: to enjoy it, one should be deprived of it occasionally.
Dost thou know what life is, my child? Hast thou comprehended the action of those springs which produce existence? Hast thou examined thyself?
Man, a mere inhabitant of the earth, cannot overstep its boundaries! But though he is confined to its crust, he may penetrate into all its secrets.
However strong, however imposing a ship may appear, it is not 'disgraced' because it flies before the tempest. A commander ought always to remember that a man's life is worth more than the mere satisfaction of his own pride. In any case, to be obstinate is blameable, and to be wilful is dangerous.
Imagine a society in which there were neither rich nor poor. What evils, afflictions, sorrows, disorders, catastrophes, disasters, tribulations, misfortunes, agonies, calamities, despair, desolation and ruin would be unknown to man!
The Yankees, the first mechanicians in the world, are engineers - just as the Italians are musicians and the Germans metaphysicians - by right of birth. Nothing is more natural, therefore, than to perceive them applying their audacious ingenuity to the science of gunnery.
It may be taken for granted that, rash as Americans usually are, when they are prudent, there is good reason for it.
Put two ships in the open sea, without wind or tide, and, at last, they will come together. Throw two planets into space, and they will fall one on the other. Place two enemies in the midst of a crowd, and they will inevitably meet; it is a fatality, a question of time; that is all.
Well, my friend, this earth will one day be that cold corpse; it will become uninhabitable and uninhabited like the moon, which has long since lost all its vital heat.
A man of merit owes himself to the homage of the rest of mankind who recognize his worth.
Solitude, isolation, are painful things and beyond human endurance.
Be it understood you are never rich when you get no advantage from it.
I seriously believed that my last hour was approaching, and yet, so strange is imagination, all I thought of was some childish hypothesis or other. In such circumstances, you do not choose your own thoughts. They overcome you.
The industrial stomach cannot live without coal; industry is a carbonivorous animal and must have its proper food.
Ah! Young people, travel if you can, and if you cannot - travel all the same!
When science has sent forth her fiat - it is only to hear and obey.
Is not a woman's heart unfathomable?
Far better to be the simplest pedestrian, with knapsack on back, stick in hand, and gun on shoulder, than an Indian prince travelling with all the ceremonial which his rank requires.
You're never rich enough if you can be richer.
I have noticed that many who do not believe in God believe in everything else, even in the evil eye.
'Movement is life;' and it is well to be able to forget the past, and kill the present by continual change.
It is certain that the inanimate objects by which you are surrounded have a direct action on the brain.
In presence of Nature's grand convulsions, man is powerless.
The sea does not belong to despots. Upon its surface men can still exercise unjust laws, fight, tear one another to pieces, and be carried away with terrestrial horrors. But at thirty feet below its level, their reign ceases, their influence is quenched, and their power disappears.
Everybody knows that England is the world of betting men, who are of a higher class than mere gamblers: to bet is in the English temperament.
You cannot oppose reasoning to pride, the principal of all the vices, since, by its very nature, the proud man refuses to listen to it.
The possession of wealth leads almost inevitably to its abuse. It is the chief, if not the only, cause of evils which desolate this world below. The thirst for gold is responsible for the most regrettable lapses into sin.
If Providence has created the stars and the planets, man has called the cannonball into existence.
In the United States, there is no project so audacious for which people cannot be found to guarantee the cost and find the working expenses.
To put up with what you cannot avoid is a philosophical principle, that may not perhaps lead you to the accomplishment of great deeds, but is assuredly eminently practical.
It is for others one must learn to do everything; for there lies the secret of happiness.
The Chinaman has only a passive courage, but this courage he possesses in the highest degree. His indifference to death is truly extraordinary. When he is ill, he sees it approach, and does not falter. When condemned, and already in the hands of an officer, he manifests no fear.
One has only to follow events, and you will be all right. The surest way is to take whatever comes as it comes.
In consequence of inventing machines, men will be devoured by them.
It must be that a man who shuts himself up between four walls must lose the faculty of associating ideas and words.