The central defining tenet of chaos magic is arguably the "meta-belief" that "belief is a tool for achieving effects". In chaos magic, complex symbol systems like Qabalah, the Enochian system, astrology or the I Ching are treated as maps or "symbolic and linguistic constructs" that can be manipulated to achieve certain ends but that have no absolute or objective truth value in themselves – a position referred to by religious scholar Hugh Urban as a "rejection of all fixed models of reality", and often summarised with the phrase "nothing is true everything is permitted".