As expressed in the Buddha's Four Noble Truths, the goal of Buddhism is to overcome suffering (duḥkha) caused by desire and ignorance of reality's true nature, including impermanence (anicca) and the non-existence of the self (anattā).[7] Most Buddhist traditions emphasize transcending the individual self through the attainment of Nirvana or by following the path of Buddhahood, ending the cycle of death and rebirth.[8][9][10] Buddhist schools vary in their interpretation of the path to liberation, the relative importance and canonicity assigned to the various Buddhist texts, and their specific teachings and practices.[11][12] Widely observed practices include taking refuge in the Buddha, the Dharma and the Sangha, observance of moral precepts, Buddhist monasticism, Buddhist meditation, and the cultivation of the Paramitas (perfections, or virtues).