Only lay down true principles, and adhere to them inflexibly. Do not be frightened into their surrender by the alarms of the timid, or the croakings of wealth against the ascendency of the people.

There are three principal means of acquiring knowledge available to us: observation of nature, reflection, and experimentation. Observation collects facts; reflection combines them; experimentation verifies the result of that combination. Our observation of nature must be diligent, our reflection profound, and our experiments exact. We rarely see these three means combined; and for this reason, creative geniuses are not common.

II. The tax which each individual is bound to pay ought to be certain, and not arbitrary.

'BUT science and art! You are denying science and art: that is you are denying that by which humanity lives.' People constantly make this rejoinder to me, and they employ: this method in order to reject my arguments without examination. 'He rejects science and art, he wishes man to revert to a state of savagery - why listen to him or discuss with him?' But this is unjust. Not only do I not repudiate science, that is, the reasonable activity of humanity, and art - the expression of that reasonable activity - but it is just on behalf of that reasonable activity and its expression that I speak, only that It may be possible for mankind to escape from the savage state into which it is rapidly lapsing thanks to the false teaching of our time. It is only on that account that I speak as I do.

All presentation, all demonstration-and the presentation of thought is demonstration-has, according to its original determination-and this is all that matters to us-the cognitive activity of the other person as its ultimate aim.

In democratic ages men rarely sacrifice themselves for another, but they show a general compassion for all the human race. One never sees them inflict pointless suffering, and they are glad to relieve the sorrows of others when they can do so without much trouble to themselves. They are not disinterested, but they are gentle.

Fortitude, the virtue which enables us to endure pain, and to banish fear, is of great use in producing tranquility. Philosophy instructs us to pay homage to the gods, not through hope or fear, but from veneration of their superior nature. It moreover enables us to conquer the fear of death, by teaching us that it is no proper object of terror; since, whilst we are, death is not, and when death arrives, we are not: so that it neither concerns the living nor the dead.

Nay, men, if any of you had heeded what I was ever foretelling and advising, ye would now neither be fearing a single man nor putting your hopes in a single man.

He who does not prevent a crime, when he can, encourages it.

I am beginning to feel that I am growing old; soon, I shall have to eat mush like children. I shall no longer be able to speak, which will be a rather great advantage for others and but a small inconvenience for myself.... The time in which I count in years is gone; that in which I count in days is here.... I had thought that the fibers of the heart would grow callous with age, it's not at all the case. I am not sure that my sensitivity hasn't increased; everything moves me, affects me.... To fade out between a man feeling your pulse and another bothering your head; not to know where one comes from, why one came, where one is going ...

Metaphysical fallacies contain the only clues we have to what thinking means to those who engage in it.

The name philosopher, which meant originally 'lover of wisdom,' has come in some strange way to mean a man who thinks it is his business to explain everything in a certain number of large books. It will be found, I think, that in proportion to his colossal ignorance is the perfection and symmetry of the system which he sets up; because it is so much easier to put an empty room tidy than a full one.

Oh, how empty is praise when it reflects back to its origin!

The irony of scientific progress is that in solving human problems it creates problems that are not humanly soluble. Science has given humans a kind of power over the natural world achieved by no other animal. It has not given humans the ability to remodel the planet according to their wishes. The Earth is not a clock that can be wound up and stopped at will. A living system, the planet will surely rebalance itself. It will do so, however, without any regard for humans.

There is the same difference between political theory and constitutional laws as there is between poetics and poetry. The illustrious Montesquieu is to Lycurgus, in the intellectual hierarchy, what Batteux is to Homer or Racine. Moreover, these two talents positively exclude each other, as can be seen by the example of Locke, who fumbled badly when he presumed to give laws to the Americans.

To be happy, we must not be too concerned with others.

Were a stranger to drop on a sudden into this world, I would show him, as a specimen of its ills, a hospital full of diseases, a prison crowded with malefactors and debtors, a field of battle strewed with carcasses, a fleet foundering in the ocean, a nation languishing under tyranny, famine, or pestilence. To turn the gay side of life to him, and give him a notion of its pleasures; whither should I conduct him? to a ball, to an opera, to court? He might justly think, that I was only showing him a diversity of distress and sorrow.

Psychologists have hitherto failed to realize that imagination is a necessary ingredient of perception itself.

In the most secret chamber of the spirit of him who believes himself convinced that death puts an end to his personal consciousness, his memory, for ever, and all unknown to him perhaps, there lurks a shadow, a vague shadow, a shadow of uncertainty, and while he says within himself, "Well, let us live this life that passes away, for there is no other!" the silence of this secret chamber speaks to him and murmurs, "Who knows!... " These voices are like the humming of a mosquito when the south-west wind roars through the trees in the wood; we cannot distinguish this faint humming, yet nevertheless, merged in the clamor of the storm, it reaches the ear.

The representation of the self-sufficiency of the I can certainly co-exist with a representation of the self-sufficiency of the thing, though the self-sufficiency of the I itself cannot co-exist with that of the thing. Only one of these two can come first, only one can be the starting point; only one can be independent. The one that comes second, just because it comes second, necessarily becomes dependent upon the one that comes first, with which it is supposed to be connected. Which of these two should come first?

Cultivators of the earth are the most valuable citizens. They are the most vigorous, the most independent, the most virtuous, and they are tied to their country and wedded to its liberty and interests by the most lasting bands. As long therefore as they can find employment in this line, I would not convert them into mariners, artisans, or any thing else. But our citizens will find employment in this line till their numbers, and of course their productions, become too great for the demand both internal and foreign.

One of the problems... both on the left and the right is that the... individual autonomy protected by liberalism tends to take more and more extreme versions... and... becomes self-undermining.

Free trade is not based on utility but on justice.

Every natural fact is a symbol of some spiritual fact.

I cannot sufficiently admire the eminence of those men's wits, that have received and held it to be true, and with the sprightliness of their judgments offered such violence to their own senses, as that they have been able to prefer that which their reason dictated to them, to that which sensible experiments represented most manifestly to the contrary. ...I cannot find any bounds for my admiration, how that reason was able in Aristarchus and Copernicus, to commit such a rape on their senses, as in despite thereof to make herself mistress of their credulity.

In the temple of science are many mansions, and various indeed are they that dwell therein and the motives that have led them thither. Many take to science out of a joyful sense of superior intellectual power; science is their own special sport to which they look for vivid experience and the satisfaction of ambition; many others are to be found in the temple who have offered the products of their brains on this altar for purely utilitarian purposes. Were an angel of the Lord to come and drive all the people belonging to these two categories out of the temple, the assemblage would be seriously depleted, but there would still be some men, of both present and past times, left inside. Our Planck is one of them, and that is why we love him. I am quite aware that we have just now lightheartedly expelled in imagination many excellent men who are largely, perhaps chiefly, responsible for the buildings of the temple of science; and in many cases, our angel would find it a pretty ticklish job to decide. But of one thing I feel sure: if the types we have just expelled were the only types there were, the temple would never have come to be, any more than a forest can grow which consists of nothing but creepers. For these people any sphere of human activity will do if it comes to a point; whether they become engineers, officers, tradesmen, or scientists depends on circumstances.Now let us have another look at those who have found favor with the angel. Most of them are somewhat odd, uncommunicative, solitary fellows, really less like each other, in spite of these common characteristics, than the hosts of the rejected. What has brought them to the temple? That is a difficult question and no single answer will cover it.

Tyrants seldom want pretexts.

The fall or scrapping of a cultural world puts us all into the same archetypal cesspool, engendering nostalgia for earlier conditions.

The history of philosophical system is the picture gallery of reason.

There are two kinds of openness, the openness of indifference-promoted with the twin purposes of humbling our intellectual pride and letting us be whatever we want to be, just as long as we don't want to be knowers-and the openness that invites us to the quest for knowledge and certitude, for which history and the various cultures provide a brilliant array of examples for examination.

Let no act be done at haphazard, nor otherwise than according to the finished rules that govern its kind.

Never give way to melancholy; resist it steadily, for the habit will encroach.

If you have been given a talent, exercise it freely and happily like the sun: give everyone from your splendour.

But if Germany, thanks to Hitler and his successors, were to enslave the European nations and destroy most of the treasures of their past, future historians would certainly pronounce that she had civilized Europe.

Preserving seeks to secure the life that already is; safeguarding secures and reproduces the conditions of becoming, of living, of futurity, where the content of that life, that living, can be neither prescribed nor predicted, and where self-determination emerges as a potential.

Music is the poor man's Parnassus.

Manuscript culture is conversational if only because the writer and his audience are physically related by the form of publication as performance.

Love the quick profit, the annual raise, vacation with pay. Want more of everything ready-made. Be afraid to know your neighbors and to die. And you will have a window in your head. Not even your future will be a mystery any more. Your mind will be punched in a card and shut away in a little drawer. When they want you to buy something they will call you. When they want you to die for profit they will let you know. So, friends, every day do somethingthat won't compute. Love the Lord. Love the world. Work for nothing. Take all that you have and be poor.Love someone who does not deserve it. Denounce the government and embracethe flag. Hope to live in that freerepublic for which it stands. Give your approval to all you cannotunderstand. Praise ignorance, for what manhas not encountered he has not destroyed.

Commoners are weightless. But he was a royal bon vivant who, no matter what, always weighed 125 kilos. I would be very surprised if he didn't have a few pounds left.

I like the dreams of the future better than the history of the past, - so good night!