This idea allows justice to be measured by an equation, each person's share of something must be justified by some relevant difference, making the equation equal. Each person should receive exactly what is proportional to what he has invested. If you work an hour more than someone, you should get paid for an extra hour. This is equal because you are compensated exactly for the work you do and the other person is not deducted in any way because they didn't work that extra hour, so they shouldn't get the extra pay. This theory allows for impartiality in making a decision, it is not based on justice due to your moral character or the consequences of your action, it is based on equal justice for all based