Numerology is understood to mean the assignment of meanings to individual numbers or combinations of numbers, whereby the numbers are given a symbolic function that goes beyond their mathematical function. Isidore of Seville was one of the most important writers and scholars of the early Middle Ages. He was the author of a mystical treatise on the allegorical meanings of numbers. He wrote: The importance of the numbers cannot be neglected. Indeed, in many places in the scriptures it becomes clear what a great mystery they contain. For it is not in vain that the praises of God say: “You made everything according to measure and number and weight."