It appears to the eye that the sun travels round the earth every day and also once every year. Thus we talk of the sun rising and setting; causing morning, noon, evening and night, as well as the seasons, spring, summer, autumn and winter, and thus days and years. Yet the sun stands unmoved, for it is a sea of fire, and it is the earth which rotates every day and travels around its orbit every year. A person, who in simplicity or ignorance thinks that the sun travels round the earth, does not destroy the natural truth, which is that the earth rotates on its axis and every year travels around the ecliptic. But if a person convinces himself of the sun's apparent motion by the reasonings of the natural mind, and more so if he does so from the Word, because it speaks of the sun rising and setting, he weakens the truth and destroys it; and afterwards he is hardly able to see it, even though he is given a visual demonstration that the whole starry sky rotates similarly every day and every year in appearance, although not a single star changes its fixed position relative to another. The movement of the sun is an apparent truth; its not moving is a genuine truth. Yet everyone speaks according to the apparent truth, saying that the sun rises and sets. This is allowed, because it could not be otherwise. But to think like this from conviction blunts and dulls the rational understanding.