Preparative adj. Tending to prepare or make ready; having the power of preparing, qualifying, or fitting; preparatory. "Laborious quest of knowledge preparative to this work."
... famous historian attributes "the peaceful successions" of modern Europe, was too little respected in those ages, in many countries of Christendom—and had no settled prescription in its favour among the Irish. Primogeniture and the whole scheme of feudal dependence seems to have been an essential preparative for modern civilization: but as Ireland had escaped the legions of Rome, so she existed without the circle of feudal organization. When that system did at length appear upon her soil it was embodied ... — A Popular History of Ireland - From the earliest period to the emancipation of the Catholics • Thomas D'Arcy McGee