I think we ought always to entertain our opinions with some measure of doubt. I shouldn’t wish people dogmatically to believe any philosophy, not even mine.
Those who forget good and evil and seek only to know the facts are more likely to achieve good than those who view the world through the distorting medium of their own desires.
Italy, and the spring and first love all together should suffice to make the gloomiest person happy.
I would never die for my beliefs because I might be wrong.
Almost everything that distinguishes the modern world from earlier centuries is attributable to science, which achieved its most spectacular triumphs in the seventeenth century.
Boredom is… a vital problem for the moralist, since half the sins of mankind are caused by the fear of it.
The coward wretch whose hand and heart Can bear to torture aught below, Is ever first to quail and start From the slightest pain or equal foe.
Fear is the main source of superstition, and one of the main sources of cruelty. To conquer fear is the beginning of wisdom.
Ethics is in origin the art of recommending to others the sacrifices required for cooperation with oneself.
The true spirit of delight, the exaltation, the sense of being more than Man, which is the touchstone of the highest excellence, is to be found in mathematics as surely as poetry.