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.
John RawlsLiberal constitutional democracy is supposed to ensure that each citizen is free and equal and protected by basic rights and liberties.
John RawlsThe fundamental criterion for judging any procedure is the justice of its likely results.
John RawlsYou might say that, if citizens are acting for the right reasons in a constitutional regime, then regardless of their comprehensive doctrines they want every other citizen to have justice. So you might say they're all working together to do one thing, namely to make sure every citizen has justice. Now that's not the only interest they all have, but it's the single thing they're all trying to do. In my language, they've striving toward one single end, the end of justice for all citizens.
John Rawls