simultaneity of cause and effect ［因果倶時］ ( inga-guji): (1) The principle that both cause and effect exist together simultaneously in a single moment of life. It contrasts with the concept of non-simultaneity of cause and effect, or cause and effect as they appear in the phenomenal world, where there inevitably seems to be a time gap between an action and its result. From the viewpoint that all phenomena exist in a single moment of life, there is no time gap between cause and effect; in other words, cause and effect are simultaneous.
(2) Cause (the nine worlds) and effect (Buddhahood) simultaneously exist in one’s life. In this sense, the simultaneity of cause and effect is revealed in the mutual possession of the Ten Worlds and the three thousand realms in a single moment of life. Nichiren’s work The Entity of the Mystic Law discusses the simultaneity of cause and effect as an attribute of the Mystic Law. It states: “He [the Buddha] perceived that there is this wonderful single Law [myōhō] that simultaneously possesses both cause and effect [renge], and he named it Myoho-renge. This single Law that is Myoho-renge encompasses within it all the phenomena comprising the Ten Worlds and the three thousand realms, and is lacking in none of them. Anyone who practices this Law will obtain both the cause and the effect of Buddhahood simultaneously” (421). Because the Law of Myoho-renge encompasses all phenomena comprising the Ten Worlds, it simultaneously possesses both the cause, or the nine worlds characterized by delusion, and the effect, the world of Buddhahood. To “obtain both the cause and the effect of Buddhahood simultaneously” means that by practicing this Law one will obtain both the cause (or practice) for attaining Buddhahood and the effect of actualizing Buddhahood simultaneously within oneself. Specifically, Nichiren is referring here to the practice of chanting Nam-myoho-renge-kyo and its function to instantaneously tap and bring forth one’s innate Buddhahood.