I am enough of an artist to draw freely upon my imagination. Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.
It isn't all over; everything has not been invented; the human adventure is just beginning.
Bold ideas, unjustified anticipations, and speculative thought, are our only means for interpreting nature: our only organon, our only instrument, for grasping her.
To live is not merely to breathe; it is to act, to make use of our organs, senses, faculties — of all those parts of ourselves which give us the feeling of existence.
The person who has lived the most is not the one who has lived the longest, but the one with the richest experiences.
Patience is bitter, but its fruit is sweet.