Luca Pacioli
By Jennifer Wolf

Luca Pacioli was born in Sansepolcro, Italy, circa 1445. Little is known of his early life, except that he was raised in Sansepolcro and received his education from the mathematician, Dominica Bragadino, and Pacioli's older friend Piero della Francesca. (Dispute later occurred over whether Pacioli plagiarized some of Piero's work.) Sometime between 1470 & 1477, Pacioli was ordained in the Franciscan order as a friar. After completion of his theological studies, he began teaching arithmetic at the universities in Perugia, Naples, and Rome.

In 1494, Pacioli wrote his most famous work, Summa de arithmetica, geometria, proportioni et proportionalita. This work, 600 pages of small print in Italian, was not aimed to serve a particular section of the Italian community, and thus served as a comprehensive guide on several aspects of mathematics and bookkeeping. Therefore, the work was studied by many mathematicians of the 16th century and influenced many of their writings. Also within Summa was Pacioli's treatise on bookkeeping, the first printed book to address a system developed by the merchants of Venice of the double-entry method, still held in esteem by the accounting community. In 1497, Pacioli was invited to teach mathematics at the court of Ludovico Sforza, duke of Milan. There, he met Leonardo da Vinci, also employed at Sforza, who helped him with this work and drawings for his books . During this time, Pacioli wrote the first part of Divina Proportione, likely the most complete and elegant book on the notion of the Golden Mean. When Sforza was later captured in 1499, by the French army, Pacioli and Leonardo journeyed to Florence.

In 1505, Pacioli was elected superior of his order for the province Romagna, and then was accepted as a member of Florence's monastery at Santa Croce. During these years, Pacioli worked on a Latin edition, as well as an Italian translation, of Euclid's Elements. In 1509, Divina Proportione and the Latin edition of Elements were published.

During this time of transition between the metaphysical approach of the Middle Ages and the rational approach of the Renaissance, Pacioli strove to logically explain the meaning of the divine proportion number with his book Divina Proportione. It marked a shift away from the faith in divine reason, a trend of the Renaissance times.

Even though Pacioli made no original contributions to mathematics, his work Summa, written in the vulgar tongue, allowed his countrymen to learn existing knowledge on the subject of algebra and thus contribute to it's advancement in the 16th century.

Luca Pacioli died in 1517, in his home town.