11. Evil is still needed in your world in order to make known goodness; night in order to be able to admire light; sickness so as to be able to appreciate health. In those other worlds there is no need of these contrasts; eternal light, eternal beauty and eternal serenity of the soul offer proportional eternal happiness, free from the perturbations caused by the anguish of material life and the contact with evil creatures, who find no access to these realms. These are the things which cause the human Spirit most difficulty in understanding. Mankind has been sufficiently ingenious as to paint the torments of hell, but could never imagine the glories of Heaven. Why not? Because, being inferior, only pain and misery have been known and as yet the celestial brightness has never been seen, so one cannot speak of that which is unknown. However, while humanity is raising itself up and cleansing its soul, horizons are expanding and mankind begins to compare the goodness which is in front of him, as well as the badness which is behind him.