I like using quotations of great mathematicians as a source of inspiration for young students. I think even a short sentence could have a great influence on forming their research interests and point of views in future. Just as an example look at the following sentences of Hugh Woodin and his student Joel Hamkins. Can you see any sign of inspiration?

Quoted from BBC documentary movie "To Infinity and Beyond":

• Prof. Doron Zeilberger (Rutgers University): Infinity may or may not exist. God may or may not exist. But in mathematics there should not be any place for neither infinity nor God!

• Prof. Hugh Woodin (Harvard University): I am so sorry for those who deny existence of infinity. It is a beautiful subject. I can say the stars don't exist and stay inside and always look down but I don't see the beauty of the stars!

Quoted from Hamkins' paper "The Set Theoretic Multiverse":

• Prof. Joel David Hamkins (City University of New York): Set theory appears to have discovered an entire cosmos of set-theoretic universes, revealing a category-theoretic nature for the subject, in which the universes are connected by the forcing relation or by large cardinal embeddings in complex commutative diagrams, like constellations filling a dark night sky.

Question. Is there a book/website which includes a collection of interesting quotations of mathematicians? It would be very interesting if it be classified by mathematical fields. e.g. Sentences about set theory, logic, algebra, analysis, probablity, etc.