Wisdom sutras ［般若経］ ( Hannya-kyō): Also known as the Perfection of Wisdom sutras or the Prajnāpāramitā sutras. A generic term for sutras that deal with the teaching of prajnā-pāramitā, or the perfection of wisdom, and expound the principle of non-substantiality. Major among the many Wisdom sutras are the Larger Wisdom Sutra, the Smaller Wisdom Sutra, the Benevolent Kings Wisdom Sutra, the Diamond Wisdom Sutra, the Heart Sutra, and the Great Wisdom Sutra, the last being a compilation of a number of Wisdom sutras. Nāgārjuna (c. 150–250) systematized the teachings of the Wisdom sutras in his Treatise on the Middle Way. In addition, the Larger Wisdom Sutra formed the basis for The Treatise on the Great Perfection of Wisdom attributed to Nāgārjuna, which expounds the doctrine of the Middle Way.