(August 17, 1601 – January 12, 1665)
Pierre de Fermat was a lawyer who treated maths as hobby. His inspirations could be traced back to the works of Diophantus of Alexandria, Gerolamo Cardano, and François Viète. Like Blaise Pascal and Christiaan Huygens, he preferred jotting random notes to publishing coherently. Still, evidence showed that he was an ingenious mathematician who motivated others. His momentous works on “Adequality” (which means “Approximate Equality”) led directly to the development of Infinitesimal Calculus. Isaac Newton would later remark that he got Calculus ideas from Fermat’s methods of dealing with tangents. Together with Pascal, Fermat is honored as founder of the Theory of Probabilities. Although he is famous today for his Last Theorem, which he scribbled as an insignificant note on the margins of a book: Diophantus’ Arithmetica, findings confirmed that he was a consummate mathematician. Apart from laying the foundations of Calculus and Theory of Probabilities, his other contributions were in Analytical Geometry, Optics and Number Theory. He was so adept in maths, as to point-out the invalidity of one of the analyses René Descartes made. This led to a squabble which prompted Descartes to say very unkind things about Fermat and Pascal. Fermat tactfully shrugged him off; remained a pacesetter, and is widely regarded as the most brilliant mathematician of his time. Even Pascal admired his brilliance, and corresponded regularly with him. His leisurely but revolutionary insights were fundamental in opening-up many new fields of maths and mathematical physics. Many concepts and theorems are named in his honor.