"The greatest discovery of all time is that a person can change his future by merely changing his attitude."

"The very existence of our senses, our reason, and our intellect, is a proof that these faculties were given us for some purpose."

"I have always felt a strong feeling of gratitude to those who have helped me in my work."

"I have always maintained that, in this country, a man can do whatever he likes, provided he is a gentleman."

"It is a wonderful fact that we can understand so much."