Quote by Paul Ehrlich
"In the end, we only regret the chances we didn't take."
More from Paul Ehrlich
"The microbe is so much smaller than ourselves that we can easily forget the fact that it stalks us all the time, waiting, and watching for the moment when we lay down our defense."
"A person who makes no mistakes has tried nothing new."
"In science there are no shortcuts to truth."
"The side-chain theory explains the formation of antibodies."