L'"Ars magna arithmeticae" nel corpus matematico di Cardano

This paper provides a quite different version of the querelle between Cardano and Tartaglia about the solution formula of the cubic equation. Reading the correspondence and the extant documents from a new point of view, it is reasonable conjecturing that the famous Cardano’s “Ars Magna” (1545) was only the final redaction of the work which had to make known the new “theory” of third and fourth degree equation. Comparing “Ars magna” with “Ars magna arithmeticae” (published posthumously in 1663, but written before 1545) and with its handwritten witness, the “Supplementum Practicae”, clearly emerges a strong interdependence among these writings. The critical comparison sheds a new light on the development of Cardano’s algebraic thought and suggests a new interpretation key of his mathematical work.