It is always a vulgar and often an unhealthy pastime, and it is a vice which does not go alone; the man who gambles will find himself capable of any evil.

Liberty is worth paying for.

In spite of the opinions of certain narrow-minded people, who would shut up the human race upon this globe, as within some magic circle it must never outstep, we shall one day travel to the moon, the planets, and the stars, with the same facility, rapidity, and certainty as we now make the voyage from Liverpool to New York!

With happiness as with health: to enjoy it, one should be deprived of it occasionally.

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?

We were alone. Where, I could not say, hardly imagine. All was black, and such a dense black that, after some minutes, my eyes had not been able to discern even the faintest glimmer.

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.

The industrial stomach cannot live without coal; industry is a carbonivorous animal and must have its proper food.

The sea is everything. It covers seven tenths of the terrestrial globe. Its breath is pure and healthy. It is an immense desert, where man is never lonely, for he feels life stirring on all sides.

Science, my lad, is made up of mistakes, but they are mistakes which it is useful to make, because they lead little by little to the truth.

It is for others one must learn to do everything; for there lies the secret of happiness.

I believe cats to be spirits come to earth. A cat, I am sure, could walk on a cloud without coming through.

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.

The Nautilus was piercing the water with its sharp spur, after having accomplished nearly ten thousand leagues in three months and a half, a distance greater than the great circle of the earth. Where were we going now, and what was reserved for the future?

When science has sent forth her fiat - it is only to hear and obey.

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.

I believe cats to be spirits come to earth. A cat, I am sure, could walk on a cloud without coming through.