(II.) The Engaku or Pratyeka Buddhas, that is, "singly enlightened," or beings in the middle state, who must extract the seeds or causes of actions, and must meditate on the twelve chains of causation, or understand the non-eternity of the world, while gazing upon the falling flowers or leaves. They attain enlightenment after four births or a hundred kalpas, according to their ability. (III.) The Bodhisattvas or Buddhas-elect, who practise the six perfections (perfect practice of alms-giving, morality, patience, energy, meditation and wisdom) as preliminaries to Nirvana, which they reach only after countless kalpas. These three grades of pupils in the mysteries of Buddha doctrine, are said to have been ordered by Shaka himself, because understanding human beings so thoroughly, he knew that one person could not comprehend two ways or vehicles (Yana) at once. People were taught therefore to practise anyone of the three vehicles at pleasure. We shall see how the later radical and democratic Japanese Buddhism swept away this gradation, and declaring but the one vehicle (éka), opened the kingdom to all believers. The second of the early Japanese schools of thought, is the Jō-jitsu,[9] or the sect founded chiefly upon the shastra which means The Book of the Perfection of the Truth, containing selections from and explanations of the true meaning of the Tripitaka. This shastra was the work of a Hindu whose name means Lion-armor, and who lived about nine centuries after Gautama. Not satisfied with the narrow views of his teacher, who may have been of the Dharmagupta school (of the four Disciplines), he made selections of the best and broadest interpretations then current in the several different schools of the Smaller Vehicle. The book is eclectic, and attempts to unite all that was best in each of the Hinayana schools; but certain Chinese teachers consider that its explanations are applicable to the Great Vehicle also. Translated into Chinese in 406 A.D., the commentaries upon it soon numbered hundreds, and it was widely expounded and lectured upon. Commentaries upon this shastra were also written in Korean by Dō-zō. From the peninsula it was introduced into Japan. This Jō-jitsu doctrine was studied by prince Shōtoku, and promulgated as a division of the school called San-Ron. The students of the Jō-jitsu school never formed in Japan a distinct organization.