Full Idea
We would wish for more than our share if we had our own way; so do we also owe to others more than their share? If the rule applies only to a just will, the rule will need a standard. The rule means that to judge fairly we must adopt others' viewpoints.
Gist of Idea
We can't want everyone to have more than their share, so a further standard is needed
Source
Gottfried Leibniz (New Essays on Human Understanding [1704], 1.02)
Book Reference
Leibniz,Gottfried: 'New Essays on Human Understanding', ed/tr. Remnant/Bennett [CUP 1996], p.91
A Reaction
The first part of this is moving towards Kant's rational overview of ethics. Leibniz is wholly right here. All ethics faces the problem that initial values are needed to get it off the ground. What's wrong with pain, or unfairness, or hatred?