“Just as in the microcosm there are seven ‘windows’ in the head (two nostrils, two eyes, two ears, and a mouth), so in the macrocosm God has placed two beneficent stars (Jupiter, Venus), two maleficent stars (Mars, Saturn), two luminaries (sun and moon), and one indifferent star (Mercury). The seven days of the week follow from these. Finally, since ancient times the alchemists had made each of the seven metals correspond to one of the planets; gold to the sun, silver to the moon, copper to Venus, quicksilver to Mercury, iron to Mars, tin to Jupiter, lead to Saturn.

From these and many other similar phenomena of nature such as the seven metals, etc., which it were tedious to enumerate, we gather that the number of planets is necessarily seven... Besides, the Jews and other ancient nations as well as modern Europeans, have adopted the division of the week into seven days, and have named them from the seven planets; now if we increase the number of planets, this whole system falls to the ground... Moreover, the satellites [of Jupiter] are invisible to the naked eye and therefore can have no influence on the earth, and therefore would be useless, and therefore do not exist.”