The number seven seems to have special status, as seen in mathematics, engineering science, natural history, psychology, and elsewhere.

Our civilization counts seven continents, seven seas, seven wonders of the ancient world, and seven heavens.

Western musical scales are composed of seven distinct notes that Pythagoras (c. 500 BC) studied mathematically. He theorized that all the elements have different vibratory frequencies that combine and collaborate in playing the grand symphony of life.

Sir Isaac Newton observed the refracted light in rainbows and after first positing five distinct colors later corrected the number to seven.

Countless psychological experiments have shown that, on average, the longest sequence a normal person can recall contains about seven items. Psychologists dubbed this limit the “magical number 7” when they discovered it in the 1950s. It is the typical capacity of what’s called the brain’s working memory.

Seven has been demonstrated to be a natural limit for the total number of interdependent elements working together as a module in a system. In engineering science, a damping system such as an electronic tank circuit or a car’s shock absorbing mechanism will cease repetitive oscillations before reaching its seventh time constant.

If you’re not yet convinced that seven is a natural limit, try folding a square piece of paper seven times. An exponential explosion of multiple layers opens to 64 squares (two to the sixth power) that prevent the seventh fold. YouTube videos show a hydraulic press turning that 7th paper fold into an unrecognizable neo-plastic glob.

The periodic table has seven rows called periods that contain 118 elements, but the seventh row has radioactive ones like radium. Some of these mysterious elements have millisecond half-lives that defy study and characterization.

Einstein said, “God does not play dice with the universe.” But God seems to have favored the number seven because it occurs more frequently than any other possible sum in a dice roll. In fact, the opposite sides of an ordinary dice always sum to seven. Casinos signal a win on a one-armed-bandit slot machine with the appearance of a row of three 7s.

As the most important symbolic number in the Hebrew Bible, seven is mentioned at least 490 times. In many contexts, it conveys not just the number seven but the idea of wholeness and perfection, representing God’s holiness, divinity, and power. It’s not surprising that the ancients regarded the number seven as having wondrous power: Joshua and Israel marched around Jericho seven times while seven priests blew seven trumpets, and the walls came crashing down (cf. Joshua 6:3-4).

Of course, God created the world in six days and rested on the seventh day. The seventh day of rest is so important to man’s well-being that Exodus 34:21 states, “Six days you shall work, but on the seventh day you shall rest.” Leviticus 23:3 says similar.

The Catholic Church has established the Seven Spiritual Gifts (wisdom, understanding, counsel, fortitude, knowledge, piety, and fear of God); the Seven Deadly Sins (lust, gluttony, greed, sloth, wrath, envy, and pride); the Seven Virtues (chastity, temperance, charity, diligence, kindness, patience, and humility) and their opposite Vices; and the Seven Sacraments (Baptism, Eucharist, Confirmation, Reconciliation, Extreme Unction, Matrimony, and Holy Orders).

To forgive more than seven times requires supernatural grace to overcome man’s natural limit. After hearing the Parable of the Unforgiving Servant, Peter approached Jesus and said, “Lord, how often shall my brother sin against me, and I forgive him? Up to seven times?”

 Jesus said to him, “I do not say to you, up to seven times, but up to seventy times seven” (Matt 18:21-22).