Religious Jews believed in immortality in a spiritual sense, and most believed that the future would include a messianic era and a resurrection of the dead. This is the subject of Jewish eschatology. Maimonides wrote much on this topic, but in most cases he wrote about the immortality of the soul for people of perfected intellect; his writings were usually "not" about the resurrection of dead bodies. Rabbis of his day were critical of this aspect of this thought, and there was controversy over his true views.