“Borden, who lived in the seventeenth century, and was a man of keen intelligence, tells us of a monk he knew, who practised bloodletting to an unlimited extent. After three bleedings, he would add a fourth, for the reason that there are four seasons, four quarters of the globe, and four cardinal points. After the fourth he took a fifth, because there are five fingers on the hand. To the fifth he would add a sixth, for did not God create the world in six days? But the number must be made seven, there being seven days in the week, and seven sages of Greece. An eighth bleeding had to follow, eight being a round number; and a ninth, because numero Deus impare gaudet—God loves odd numbers.”

— Maxime Du Camp on the superstitious nature of mediaeval medicine¹