As expressed in the Buddha's Four Noble Truths, the goal of Buddhism is to overcome suffering ("duḥkha") caused by desire or craving ("taṇhā"), attachment to a static self, and ignorance ("avidya") of the true nature of reality. 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. 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. 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).