A-1.4: Meaning of Good and Bad
The basic premise of this school of thought is that the good of the acts of those morally responsible is what the Lawgiver (syn. Allah or His messenger (Allah bless him and give him peace) ) has indicated is good by permitting it or asking it be done. And the bad is what the Lawgiver has indicated is bad by asking it not be done.
The good is not what reason considers good, nor the bad what reason considers bad. The measure of good and bad, according to this school of thought, is the sacred Law not reason (dis:W-3).