@incollection {1043033, title = {From the second unknown to the symbolic equation}, booktitle = {Philosophical Aspects of Symbolic Reasoning in Early Modern Mathematics}, volume = {26}, year = {2010}, pages = {57{\textendash}102}, publisher = {College Publications}, abstract = {

The symbolic equation slowly emerged during the course of the sixteenth century as a new mathematical concept as well as a mathematical object on which new operations were made possible. Where historians have of- ten pointed at Francois Vi{\`e}te as the father of symbolic algebra, we would like to emphasize the foundations on which Vi{\`e}te could base his logistica speciosa. The period between Cardano’s Practica Arithmeticae of 1539 and Gosselin’s De arte magna of 1577 has been crucial in providing the necessary build- ing blocks for the transformation of algebra from rules for problem solving to the study of equations. In this paper we argue that the so-called “second unknown” or the Regula quantitates steered the development of an adequate symbolism to deal with multiple unknowns and aggregates of equations. Dur- ing this process the very concept of a symbolic equation emerged separate from previous notions of what we call “co-equal polynomials”.

}, isbn = {978-1-84890-017-2}, author = {Heeffer, Albrecht}, editor = {Heeffer, Albrecht and Van Dyck, Maarten} }