"I have always endeavoured to be guided by reason, and not by prejudice."

"I have often been accused of being too sanguine in my expectations; but time will show whether I am right or wrong."

"The human mind is capable of great things; but it is also capable of great errors."

"The progress of science is slow, but it is sure."

"The most valuable possessions are those which we acquire by our own exertions."