Mencius - Book 6, Part 1, Chapter 1

The philosopher Kâo said, 'Man's nature is like the ch'î-willow , and righteousness is like a cup or a bowl. The fashioning benevolence and righteousness out of man's nature is like the making cups and bowls from the ch'î-willow.'

Mencius replied, 'Can you, leaving untouched the nature of the willow, make with it cups and bowls? You must do violence and injury to the willow, before you can make cups and bowls with it. If you must do violence and injury to the willow in order to make cups and bowls with it, on your principles you must in the same way do violence and injury to humanity in order to fashion from it benevolence and righteousness! Your words, alas would certainly lead all men on to reckon benevolence and righteousness to be calamities.'

~ James Legge translation via nothingistic.org ~

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