Looking at Pure Land Buddhism from the point of the Four-Wheels (Skt. Catvāri deva-manuṣyāṇāṃ cakrāṇi), we can see the relation between this concept beginning in Early Buddhism and the contents of practice in later Pure Land Buddhism. In this sense, a prototype of Pure Land Buddhism may be traced back to Early Buddhism.
The collation with the texts of early stages, including those of various śrāvaka-schools, where the Four-Wheels is accepted and developed, still remains as a problem, but at least we can point out an apparent similarity of the concept of the First-Wheel, choosing the circumstance of practices, which was to be reconstructed as the concept of rebirth, as reflected in the texts of the Yogācāras, and that Sukhāvatī is the very suitable circumstance for the practice of śamatha-vipaśyanā.
