A mathematician is a device for turning coffee into theorems. (Paul Erdos)

When one person suffers from a delusion it is called insanity; when many people suffer from a delusion it is called religion. (Robert Pirsig)

Only two things are infinite, the universe and human stupidity, and I’m not sure about the former. (Albert Einstein)

Problems worthy of attack prove their worth by fighting back. (Paul Erdos)