[E]ach person is to have an equal right to the most extensive basic liberty compatible with a similar liberty for others.

Peace surely is a good reason, yes. But there are other reasons too.

A comprehensive doctrine, either religious or secular, aspires to cover all of life. I mean, if it's a religious doctrine, it talks about our relation to God and the universe; it has an ordering of all the virtues, not only political virtues but moral virtues as well, including the virtues of private life, and the rest. Now we may feel philosophically that it doesn't really cover everything, but it aims to cover everything, and a secular doctrine does also.

Of course, we know that not everyone agrees with assisted suicide, but people might agree that one has the right to it, even if they're not themselves going to exercise it.

Man is a historical being : The realisations of the powers of human individuals living at any one time takes the cooperation of many generations (or even societies) over a long period of time. By contrast with humankind, every individual animal can and does do what for the most part it might do, or what any other of its kind might or can do that lives at the same time.

I live in a country where 90 or 95 percent of the people profess to be religious, and maybe they are religious, though my experience of religion suggests that very few people are actually religious in more than a conventional sense.

A just society is a society that if you knew everything about it, you'd be willing to enter it in a random place.