Every cause produces more than one effect.
Everyone you meet always asks if you have a career, are married, or own a house as if life was some kind of grocery list. But no one ever asks you if you are happy.
Nothing in life is to be feared, it is only to be understood. Now is the time to understand more, so that we may fear less.
If you are going through hell, keep going.
Natural science does not simply describe and explain nature: it is part of the interplay between us and nature.
An expert is a person who has made all the mistakes that can be made in a very narrow field.
Never mistake motion for action.
Anything that gives us new knowledge gives us an opportunity to be more rational.
The educated differ from the uneducated as much as the living differ from the dead.
To him who looks upon the world rationally, the world in its turn presents a rational aspect. The relation is mutual.