Exertion

A hundred times every day I remind myself that my inner and outer life depend on the labours of other men living and dead and that I must exert myse...

Albert Einstein

Difficulties should act as a tonic. They should spur us to greater exertion.

B. C. Forbes

The true value of a man is not determined by his possession, supposed or real, of Truth, but rather by his sincere exertion to get to the Truth.

Gotthold Ephraim Lessing