A clever person solves a problem. A wise person avoids it.
A hundred times every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving.
A man's ethical behavior should be based effectually on sympathy, education, and social ties; no religious basis is necessary. Man would indeed be in a poor way if he had to be restrained by fear of punishment and hope of reward after death.
A man's moral worth is not measured by what his religious beliefs are but rather by what emotional impulses he has received from Nature during his lifetime.
A person starts to live when he can live outside himself.
A table, a chair, a bowl of fruit and a violin what else does a man need to be happy?
A theory is the more impressive the greater the simplicty of its premises is.
About Newton: Nature to him was an open book, whose letters he could read without effort.
All these constructions and the laws connecting them can be arrived at by the principle of looking for the mathematically simplest concepts and the link between them.
Although words exist for the most part for the transmission of ideas, there are some which produce such violent disturbance in our feelings that the role they play in the transmission of ideas is lost in the background.