“You can do what you will, but in any given moment of your life you can will only one definite thing.”

“As the biggest library if it is in disorder is not as useful as a small but well-arranged one, so you may accumulate a vast amount of knowledge but it will be of far less value to you than a much smaller amount if you have not thought it over for yourself; because only through ordering what you know by comparing every truth with every other truth can you take complete possession of your knowledge and get it into your power.”

“Mensch kann tun was er will; er kann aber nicht wollen was er will. (One can choose what to do, but not what to want.)”

“There is one thing that, more than any other, throws people absolutely off their balance — the thought that you are dependent upon them. This is sure to produce an insolent and domineering manner towards you. There are some people, indeed, who become rude if you enter into any kind of relation with them; for instance, if you have occasion to converse with them frequently upon confidential matters, they soon come to fancy that they can take liberties with you, and so they try and transgress the laws of politeness. This is why there are so few with whom you care to become more intimate, and why you should avoid familiarity with vulgar people. If a man comes to think that I am more dependent upon him than he is upon me, he at once feels as though I had stolen something from him; and his endeavor will be to have his vengeance and get it back. The only way to attain superiority in dealing with men, is to let it be seen that you are independent of them.”

“Philosophy ... is a science, and as such has no articles of faith; accordingly, in it nothing can be assumed as existing except what is either positively given empirically, or demonstrated through indubitable conclusions.”

“Just as one spoils the stomach by overfeeding and thereby impairs the whole body, so can one overload and choke the mind by giving it too much nourishment. For the more one reads the fewer are the traces left of what one has read; the mind is like a tablet that has been written over and over. Hence it is impossible to reflect; and it is only by reflection that one can assimilate what one has read. If one reads straight ahead without pondering over it later, what has been read does not take root, but is for the most part lost.”

“If at any moment Time stays his hand, it is only when we are delivered over to the miseries of boredom.”