Not obligate; optional, discretionary or elective.
That grants permission or power to do something.
Able to perform a particular life function, or to live generally, in more than one way.
Of or relating to faculty, especially to mental faculty.
At which a given function is positive.
Not restrained; not confined by precise limits.
Lax in moral or religious principles.
Tolerant, especially of other people's religious views.
A person who is tolerant of others' religious views.