The Mystical Number 7

Symbolically thinking, seven is the granddaddy of sacred numbers.

In the Bible there are seven days of creation, seven virtues, seven deadly sins, seven pillars of wisdom, seven sorrows (and joys) of the Virgin, seven divisions of the Lord's Prayer, seven sacraments, seven cardinal sins, and seven graces.

The Book of Revelations, the last chapter of the New Testament, is built around the number seven. It speaks of seven trumpets (heralding the end of days), seven golden lamp stands (representing the seven churches of the apocalypse), seven golden stars (representing the seven angels of the apocalypse), seven spirits before the throne of God, seven plagues, seven bowls of wrath, seven vials, seven judgments, seven kings, a seven-headed beast, a dragon with seven heads wearing seven diadems, a lamb with seven eyes, and an earthquake that kills seven thousand people.

The three most important Jewish feasts each lasts seven days, as do Levitical purifications, and the sabbatical occurs every seven years. Ancient astrologers recognized seven plants. In Islam, there are seven heavens and seven holy sleepers. Buddhists revere the seven treasures. In many religions, the seventh son of a seventh son is endowed with magical powers. Japanese folklore has seven gods of good fortune.

There are seven days in a week, seven seas, seven continents, seven wonders of the ancient world, and seven whole notes in a Western scale. Shakespeare famously wrote of the seven ages of man. The average number of objects a human being can retain in short-term memory is seven. (This is why phone numbers have seven digits.)

Taken from the book Fooling Houdini by Alex Stone, published by HarperCollins in 2012.