People can make arguments from the Bible if they want to. But I want them to see that they should also give arguments that all reasonable citizens might agree to.

If A were not allowed his better position, B would be even worse off than he is.

There are infinitely many variations of the initial situation and therefore no doubt indefinitely many theorems of moral geometry.

Now the good of political life is a great political good. It is not a secular good specified by a comprehensive doctrine like those of Kant or Mill. You could characterize this political good as the good of free and equal citizens recognizing the duty of civility to one another: the duty to give citizens public reasons for one's political actions.

Properly understood, then, the desire to act justly derives in part from the desire to express most fully what we are or can be, namely free and equal rational beings with the liberty to choose.

Any comprehensive doctrine, religious or secular, can be introduced into any political argument at any time, but I argue that people who do this should also present what they believe are public reasons for their argument. So their opinion is no longer just that of one particular party, but an opinion that all members of a society might reasonably agree to, not necessarily that they would agree to. What's important is that people give the kinds of reasons that can be understood and appraised apart from their particular comprehensive doctrines.

A society regulated by a public sense of justice is inherently stable.