1768 – 1822
Jean-Robert Argand (1768–1822) was a French-Swiss amateur mathematician best known for his 1806 publication introducing the geometric representation of complex numbers now called the Argand diagram. His work contributed to the foundations of mathematics by giving imaginary numbers a concrete geometric interpretation, placing him within early philosophy of mathematics and debates over the reality of abstract mathematical objects.
Introduced the Argand diagram, representing complex numbers as points in a two-dimensional plane (1806)
Provided a geometric foundation for imaginary numbers, supporting their mathematical legitimacy
Contributed to early debates on the ontological status of abstract mathematical entities
Published independently of Gauss and Wessel on the geometric interpretation of complex numbers