It doesn't absolutely require a heavenly mandate nor a tedious search through the thick tomes of the philosophers to discover what "good" is. A self-revelation can occur on the subject.

     It can be worked out by almost any person.

     If one were to think over how he or she would like to be treated by others, one would evolve the human virtues. Just figure out how you would want people to treat you.

L. Ron Hubbard