Ideally citizens are to think of themselves as if they were legislators and ask themselves what statutes, supported by what reasons satisfying the criterion of reciprocity, they would think is most reasonable to enact.

Intuitionism is not constructive, perfectionism is unacceptable.

An intuitionist conception of justice is, one might say, but half a conception.

Certainly it is wrong to be cruel to animals and the destruction of a whole species can be a great evil. The capacity for feelings of pleasure and pain and for the form of life of which animals are capable clearly impose duties of compassion and humanity in their case.

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.

Public reason arguments can be good or bad just like other arguments.

Ideally a just constitution would be a just procedure arranged to insure a just outcome.