“Eureka! [I have found it!] On discovery of a method to test the purity of gold.”

“Eureka! (I have found it!).”

“Love from its very nature must be transitory. To seek for a secret that would render it constant would be as wild a search as for the philosopher's stone or the grand panacea: and the discovery would be equally useless, or rather pernicious to mankind. The most holy band of society is friendship.”

“Give me a place to stand, and a lever long enough, and I will move the world.”

“Mathematics reveals its secrets only to those who approach it with pure love, for its own beauty.”

“Man has always learned from the past. After all, you can't learn history in reverse!”

“Rise above oneself and grasp the world.”