Glen Anderson of Newcastle University Australia has published a thought-provoking and extremely well documented examination of secession as a concept in international law and world affairs. The excellent and exhaustively footnoted overview ends with this gem:
Arriving at a justified definition of secession is critical in the context of international law and relations as secession is a well-recognised method of state creation. Rather than assuming (erroneously) that there is a commonly accepted definition of secession, or propounding an arbitrary definition devoid of justification, it is incumbent upon scholars to invoke a more exacting approach. (emphasis mine)
The whole piece is worth checking out.