Unmanifest-karma (無表業) is precisely what we call the karmic-power (業力), which is the lingering remnant power of bodily and mind actions of a sentient being. General understanding of karmic-power is confined to the force that could bring the happy or painful retribution, which arise from the bodily, verbal, and mind actions. Indeed, the bodily and verbal actions, which driven by deliberate wholesome or unwholesome mind, not only leave behind the power that could bring about the happy or painful retribution in the future, but also give rise to a sustaining karmic-power that could continuingly influence every bodily and verbal action of a sentient being in the present moment. The sustaining karmic-power, which has not yet elapse, is the so called "unmanifest-karma" (avijbapti-karma). It is also recognized as the "unmanifest-morality" (avijbapti-wila), which is the essence of precepts (戒體), for it could let one to do wholesome deeds and prevent one from unwholesome deeds. In respect of its nature, the Sarvastivadins classified unmanifest-karma as form-element for it could restrain bodily and verbal actions. Hence, unmanifest-karma or unmanifest-morality also recognized as unmanifest-form-element (avijbapti-rupa). The thought of unmanifest-karma as a form-element was established in the development of Abhidhamma schools. Around 150 BCE, the dogma of unmanifest-karma as a form-element was fully established when Kaccayana composed the Abhidharma-jbana-prasthana, which is to form the doctrine of "the reality of past-present-future" (三世實有). The present study discovered four purposes for the establishment of unmanifest-karma. First, to advocate the dogma of the essence of precepts (戒體論). This is to emphasize the embodiment of wila-samadhi-prajba as a normal path. Second, to establish the dogma of bodily and verbal unmanifest-karma apart from the three actions, which are the bodily, verbal, and mind actions. This is to explain the continuing growth of evil karma and good karma. Third, under the condition of "instructing others to do", the unmanifest-karma is an essential evidence for the ascription of ultimate karmic causal effect. Fourth, to prove that the unmanifest-karma, which gradually elapsed into the past, is the heterogeneous cause (異熟因), which could bring about the painful or happy retributions. It is also the contributing cause of directive karma (引業) and the heterogeneous cause of particularizing karma (滿業). In addition, from the discussion on the ascription of the responsibility of "instructing others to do", the study has found out reasonable theoretical foundation for the idea of "rejoicing in the merit of others" (隨喜功德) in Mahayana. It testifies as to why, "the like will the like use" (同願同行) in Mahayanic rejoicing in the merit of others, the higher participating in the fulfillment of a great work the greater accumulation of merit and virtue to be gathered. Finally, the fact that the Sarvastivadin has rigorous stipulations in the upasaka precepts and the upavasa precepts indicates that the Sarvastivadin Abhidharmikas, who make much account of bodily and verbal cultivation, may not have enthusiastic devotion of a religious teacher in social reformation. In addition, they may not be able to ad
