Luca Bartolomes Pacioli | Biography

Luca Bartolomes Pacioli is widely regarded as the developer of the double-entry accounting system, which revolutionized the way people kept track of money and is still the dominant accounting method in use today. He wrote extensively on the subject and helped to make double entry the standard accounting practice throughout the world.

Pacioli was born in Sansepolcro, Italy in about 1445. For some reason not clear today, the boy grew up with the nearby Befolci family. It is said that the great artist Piero de la Francesca fostered and encouraged Pacioli's love of mathematics from an early age, perhaps giving him part of his formal education. As a young man, Pacioli served as an apprentice to a wealthy Venetian merchant, also living with him and tutoring his three sons while learning mathematics at a nearby church school.

After writing his first work on arithmetic in 1470, Pacioli stayed briefly in Rome at the home of architect Leone Alberti, who served as Pacioli's patron and friend. Sometime in the next several years, however, Pacioli was ordained as a friar in the Franciscan order and completed theological studies at an Italian monastery. Some sources say that Alberti's death prompted this sudden, life-changing action. Pacioli then began wandering throughout Italy, teaching arithmetic in some of the larger cities before settling at the University of Perugia from 1477 to 1480. There he wrote a treatise on mathematics in 1478.

Beginning in 1481, Pacioli started another period of itinerant teaching, working for brief periods in Zara (in what is now Croatia), Naples, and Rome, during which he completed the equivalent of what today would be a doctoral degree. In 1489 he returned to Sansepolcro and spent a few years there writing his largest work, Summa de Arithmetica, Geometrica, Proportioni et Proportionalita (Everything about Arithmetic, Geometry, and Proportion). He took the manuscript to Venice, where it was printed on Guttenberg's expensive new metal type machine, and published it in 1494. Although the book had 36 chapters on bookkeeping, the topic represented only a fraction of what the book covered, since it was intended as a compendium of existing mathematical knowledge. Thus, it did not contain a great deal of original work, but rather summarized the contributions of many important mathematicians. Pacioli openly acknowledged his use of their material, although he would encounter much criticism for his liberal use of others' work.

Pacioli's bookkeeping chapters, collectively entitled "De computis et scripturis" ("Of Reckonings and Writings"), discussed in detail the double entry system, known then as "the method of Venice," that would change accounting forever. Although Benedetto Cotrugli is actually thought to have invented the system, it was Pacioli who developed and codified it in his huge work, making it accessible to anyone who could use it by writing the treatise in laymen's terms. The first 16 chapters describe the basic layout of books and accounts. The Pacioli system comprises three parts: the memorandum, for recording transactions as they occurred; the journal, a private account book for the merchant; and the ledger, which features a double page with debits on the left and credits on the right. The remaining 20 chapters concern merchant-related issues such as deposits and withdrawals, drafts, barter transactions, expense disbursements, and closing and balancing the books. The only real differences between Pacioli's double entry accounting and that in use today are related to the needs of larger-scale businesses.

In 1496, Pacioli accepted an invitation to teach mathematics in Milan at the royal court. There he met Leonardo da Vinci, with whom he soon became close friends. In fact, when the French Army marched into Milan in 1499, the men fled together to Venice. In 1500, Pacioli began teaching geometry at the University of Pisa, remaining there until 1506. Meanwhile, Pacioli and da Vinci had remained close friends; Da Vinci even illustrated the cover and some of the figures of Pacioli's 1509 trilogy Divina proportione (The Golden Ratio).

Pacioli returned to the University of Perugia as a lecturer in 1510. He taught again in Rome in 1514, but soon returned to Sansepolcro, where he died in about 1517.