While the actual origin of the terms debit and credit is unknown, the first known recorded use of the terms is Venetian Luca Pacioli's 1494 work, Summa de Arithmetica, Geometria, Proportioni et Proportionalita (translated: Everything About Arithmetic, Geometry, Proportions and Proportionality). Pacioli devoted one section of his book to documenting and describing the double-entry bookkeeping system in use during the Renaissance by Venetian merchants, traders and bankers. This system is still the fundamental system in use by modern bookkeepers.[4]
One theory is that in its original Latin, Pacioli's Summa used the Latin words debere (to owe) and credere (to entrust) to describe the two sides of a closed accounting transaction. When his work was translated, the Latin words debere and credere became the English debit and credit. Under this theory, the abbreviations Dr (for debit) and Cr (for credit) derive from the original Latin.[5] However, Sherman[6] casts doubt on this idea because Pacioli does not use debere nor Dr nor any word of similar root in his journal entries. In fact Pacioli uses Per (Latin for "from") for the left side of the sentence and A (Latin for "to") to begin the right side. Sherman goes on to say that the earliest text he found that actually uses "Dr." as an abbreviation in this context was an English text, the third edition (1633) of Ralph Handson's book Analysis or Resolution of Merchant Accompts[7] and that Handson uses Dr. as an abbreviation for the English word "debtor." (Sherman could not locate a first edition, but speculates that it too used Dr. for debtor.)
Jackson[8] notes that "debtor" need not be a person, but can be an abstract operator (cf. "divisor" in math) "...it became the practice to extend the meanings of the terms ... beyond their original personal connotation and apply them to inanimate objects and abstract conceptions...".