The six stages of Bodhisattva developments as defined in the Tiant 'ai 圓教, i. e. Perfect, or Final Teaching, in contrast with the previous, or ordinary six developments of 十信, 十住, 十行, etc., as found in the 別教 Differentiated or Separate school. The Tiantai six are: (1) 理即 realization that all beings are of Buddha-nature; (2) 名字即 the apprehension of terms, that those who only hear and believe are in the Buddha. law and potentially Buddha; (3) 觀行即 advance beyond terminology to meditation, or study and accordant action; it is known as 五品觀行 or 五品弟子位; (4) 相似即 semblance stage, or approximation to perfection in purity, the 六根清淨位, i. e. the 十信位; (5) 分證即 discrimination of truth and its progressive experiential proof, i. e. the 十住, 十行, 十迴向, 十地, and 等覺位 of the 別教 known also as the 聖因 cause or root of holiness. (6) 究竟即 perfect enlightenment, i. e. the 妙覺位 or 聖果 fruition of holiness. (1) and (2) are known as 外凡 external for, or common to, all. (1) is theoretical; (2) is the first step in practical advance, followed by (3) and (4) styled 內凡 internal for all, and (3), (4), (5), and (6) are known as the 八位 the eight grades.