Once we’ve gotten to God, the argument goes, getting to the world around us is easy. Since God is a perfect being, he would not allow us to be deceived. So, given that God exists, there can be no evil demon and no dreams or sensory illusions that persist for one’s whole life. God will ensure that our impressions of the external world are, by and large, accurate. For him to do anything else would be imperfect. So the external world exists and is much as we thought it was. Hallelujah!
