It often takes more courage to change one's opinion than to stick to it.

Nothing is more conducive to peace of mind than not having any opinion at all.

Brevity: To say at once whatever is to be said.

Do we write books so that they shall merely be read? Don't we also write them for employment in the household? For one that is read from start to finish, thousands are leafed through, other thousands lie motionless, others are jammed against mouseholes, thrown at rats, others are stood on, sat on, drummed on, have gingerbread baked on them or are used to light pipes.

A writer who wishes to be read by posterity must not be averse to putting hints which might give rise to whole books, or ideas for learned discussions, in some corner of a chapter so that one should think he can afford to throw them away by the thousand.

Cautiousness in judgment is nowadays to be recommended to each and every one: if we gained only one incontestable truth every ten years from each of our philosophical writers the harvest we reaped would be sufficient.

I cannot say whether things will get better if we change; what I can say is they must change if they are to get better.