Etymologies

Description

This work is a complete English translation of the Latin Etymologies of Isidore, Bishop of Seville (c.560-636). Isidore compiled the work between c.615 and the early 630s and it takes the form of an encyclopedia, arranged by subject matter. It contains much lore of the late classical world beginning with the Seven Liberal Arts, including Rhetoric, and touches on thousands of topics ranging from the names of God, the terminology of the Law, the technologies of fabrics, ships and agriculture to the names of cities and rivers, the theatrical arts, and cooking utensils. Isidore provides etymologies for most of the terms he explains, finding in the causes of words the underlying key to their meaning. This book offers a highly readable translation of the twenty books of the Etymologies, one of the most widely known texts for a thousand years from Isidore's time.

p. 90 // PDF p. 104:

iv. What numbers do for us (Quid praestent numeri)

1. The reckoning of numbers ought not to be despised, for in many passages of sacred writings it elucidates how great a mystery they hold. Not for nothing it is said in praise of God (Wisdom 11:21), “Thou hast ordered all things in measure, and number (numerus), and weight.”
2. The [number] that contains six units (senarius), which is perfect in its own parts, declares the completion of the world by a certain signification of its number. Likewise for the forty days during which Moses and Elijah and the Lord himself fasted: without an understanding of numbers, the span of days is unintelligible.
3. So also there are other numbers in the Sacred Scriptures whose figurative meaning cannot be resolved except by those skilled in the knowledge of the mathematical art. It is even our lot to depend on the discipline of numbers to some extent when through it we name the hours, when we dispute about the course of the months, and when we recognize the duration of the turning year.
4. Indeed, through numbers, we are provided with the means to avoid confusion. Remove numbers from all things, and everything perishes. Take away the computation of time, and blind ignorance embraces all things; those who are ignorant of the method of calculation cannot be differentiated from the other animals.

On the previous page, iii. What a number is (Quid sit numerus) , he says "The term ‘coin’ (nummus) gave its name to ‘number’ (numerus)". I never knew that!

*He discusses perfect numbers in §V.11 (the next page):

11. A perfect (perfectus) number is one that is completely filled up by its own parts, as, for example, 6, for it has 3 parts: 6, 3, and 2. The part that occurs 6 times is 1, the part that occurs 3 times is 2, and the part that occurs 2 times is 3. When these parts are added together, that is, when 1, 2, and 3 are summed up together, they make (perficere , ppl. perfectus) the number 6. Perfect numbers that occur within 10 include 6; within 100, 28; and within 1000, 496.