Do nothing which is of no use.
Read more
By the same author and on kindred topics.
A thousand days of training is called forging; ten thousand days of training is called tempering.
Miyamoto Musashi, 1584–1645 -
Miyamoto Musashi, 1584–1645 -
Miyamoto Musashi, 1584–1645 
Niccolò Machiavelli, 1469–1527 
The mind of a master does not stop on any one thing, even for an instant.
Takuan Sōhō, 1573–1645 -
Act without letting your mind be captured by thinking about every move.
Takuan Sōhō, 1573–1645