In the 2nd century AD, Irenaeus distinguished paradise from heaven. In "Against Heresies", he wrote that only those deemed worthy would inherit a home in heaven, while others would enjoy paradise, and the rest live in the restored Jerusalem (which was mostly a ruin after the Jewish–Roman wars but was rebuilt beginning with Constantine the Great in the 4th century). Origen likewise distinguished paradise from heaven, describing paradise as the earthly "school" for souls of the righteous dead, preparing them for their ascent through the celestial spheres to heaven.