Its an ancient article that is hard to find on this site, but I think for those interested in learning more about the intricacies of bid'ah will find it interesting.
This is the principle of original permissibility:
The following is the text of a talk given by Shaikh Nuh Ha Mim Keller at Nottingham and Trent University on Wednesday 25th January 1995
There are few topics that generate as much controversy today in Islam as what is sunna and what is bida or reprehensible innovation, perhaps because of the times Muslims live in today and the challenges they face.
Without a doubt, one of the greatest events in impact upon Muslims in the last thousand years is the end of the Islamic caliphate at the first of this century, an event that marked not only the passing of temporal, political authority, but in many respects the passing of the consensus of orthodox Sunni Islam as well.