The most valuable discoveries have found their origin in the most trivial accidents.
The best plan is to profit by the folly of others.
The depth of darkness to which you can descend and still live is an exact measure of the height to which you can aspire to reach.
Nulla dies sine linea - Not a day without a line.
No mortal man, moreover is wise at all moments.
On a farm the best fertilizer is the master's eye.