Fashions of Belief by George Bernard Shaw — Read

Now matters of taste are mostly also matters of fashion. We are conscious of a difference between medieval fashions in belief and modern fashions. For instance, though we are more credulous than men were in the Middle Ages, and entertain such crowds of fortunetellers, magicians, miracle workers, agents of communication with the dead, discoverers of the elixir of life, transmuters of metals, and healers of all sorts, as the Middle Ages never dreamed of as possible, yet we will not take our miracles in the form that convinced the Middle Ages. Arithmetical numbers appealed to the Middle Ages just as they do to us, because they are difficult to deal with, and because the greatest masters of numbers, the Newtons and Leibnitzes, rank among the greatest men. But there are fashions in numbers too.

The Middle Ages took a fancy to some familiar number like seven; and because it was an odd number, and the world was made in seven days, and there are seven stars in Charles's Wain, and for a dozen other reasons, they were ready to believe anything that had a seven or a seven times seven in it. Seven deadly sins, seven swords of sorrow in the heart of the Virgin, seven champions of Christendom, seemed obvious and reasonable things to believe in simply because they were seven. To us, on the contrary, the number seven is the stamp of superstition. We will believe in nothing less than millions. A medieval doctor gained his patient's confidence by telling him that his vitals were being devoured by seven worms. Such a diagnosis would ruin a modern physician.