Mencius - Book 7, Part 1, Chapter 29

Mencius said, 'A man with definite aims to be accomplished may be compared to one digging a well. To dig the well to a depth of seventy-two cubits, and stop without reaching the spring, is after all throwing away the well.'

~ James Legge translation via nothingistic.org ~

 Go here to read the introductory post to this serialized version of the Works of Mencius.