If you always do what you've always done, you'll always get what you've always got.
Henry Ford
The errors which arise from the absence of facts are far more numerous and more durable than those which result from unsound reasoning respecting true data.
Charles Babbage
No plan survives contact with reality. (Inspired by “No plan survives the first enemy contact”)
Helmuth von Moltke
Success consists of going from failure to failure without loss of enthusiasm.
Winston Churchill
All our knowledge has its origins in our perceptions.
Leonardo da Vinci
If an engineer has not had some failures, it is merely evidence that his practice has not been sufficiently extensive.
Benjamin Baker
When everything seems to be going against you, remember that the airplane takes off against the wind, not with it.
Henry Ford
The secret to success is constancy of purpose.
Benjamin Disraeli
Obstacles are those frightful things you see when you take your eyes off your goal.
Henry Ford
An investment in knowledge still bears the best interests.
Benjamin Franklin