Pacioli

Luca Bartolomes Pacioli (c. 1447 – 1517) was an Italian mathematician and Franciscan friar who played a central role in the Renaissance as a popularizer and educator of mathematical knowledge. Born in Borgo Sansepolcro, he traveled through northern Italy and later worked at the court of Ludovico Sforza in Milan, where he taught mathematics and engaged in collaborations with artists and engineers, including Leonardo da Vinci.

Pacioli is best known for his encyclopedic treatise Summa de arithmetica, geometria, proportioni et proportionalità, published in 1494. The Summa covers arithmetic, algebra, geometry, and proportion, and it is widely recognized for containing the first published description of the double-entry bookkeeping system, including a practical ledger example that helped standardize commercial accounting in Europe. He also authored De divina proportione, published in 1509, a work on proportion and geometry with illustrations by Leonardo da Vinci. The text explores the golden ratio and the geometry of the five Platonic solids, linking mathematical theory to artistic and architectural design.

Pacioli’s collaboration with Leonardo da Vinci extended to the visual treatment of mathematical ideas, and his writings helped fuse mathematical practice with art and craft during the Renaissance. He is often regarded as the father of accounting for his systematic exposition of double-entry bookkeeping, a method that would underlie commercial finance for centuries. Pacioli died in 1517, leaving a lasting legacy in mathematics, accounting, and the broader culture of proportion in Renaissance Europe.