Whereas the god receives a gift in the honorific sacrifice, he demands a life in the piacular.
Robertson Smith (Religion of the Semites, new ed., 1894, pp. 191, 290, 411), who, regarding Adonis as the swine-god, characterizes the Adonia as an annual piacular sacrifice (of swine), "in which the sacrifice has come to be overshadowed by its popular and dramatic accompaniments, to which the Greek celebration, not forming part of the state religion, was limited."
The first form of his theory distinguishes (i.) honorific, (ii.) piacular and (iii.) mystical or sacramental sacrifices; but the latter type is traced back to the same cycle of ideas as that in which the piacular sacrifice originated.
The unity of procedure consists in the fact that every sacrifice involves putting the divine in communication with the profane by an intermediary - the victim - which may be piacular or honorific, a messenger or a means of divination, a means of alimenting the eternal life of the species or a source of magical energy which the rite diffuses over objects in its neighbourhood.
Frazer has put forward the view that while the sacrifice of the god may have been piacular, it was also intended to preserve his divine life against the inroads of old age.