(Pierre), who was councillor of the parliament of Toulouse in France, flourished in the 17th century, and died in 1663. He was a man of great talents, and a very general scholar; but being contemporary and intimately connected with Des Cartes, Merienne, Torricelli, and Huygens, he was naturally led to devote much of his time to the mathematical sciences. He was (says Dr Hutton) a first rate mathematician, and possessed the finest taste for pure and genuine geometry, which he contributed greatly to improve, as well as algebra.

Fermat was author of, 1. A Method for the Quadrature of all sorts of Parabolas.—2. Another on Maximums and Minimums: which serves not only for the determination of plane and solid problems, but also for drawing tangents to curve lines, finding the centres of gravity in solids, and the resolution of questions concerning numbers: in short, a method very similar to the fluxions of Newton.—3. An Introduction to Geometric Loci, plane and solid.—4. A Treatise on Spherical Tangencies: where he demonstrates in the solids, the same things as Vieta demonstrated in planes.—5. A Refutation of Apollonius's two books on Plane Loci. —6. A General Method for the dimension of Curve Lines. Besides a number of other smaller pieces, and many letters to learned men; several of which are to be found in his Opera Varia Mathematica, printed at Toulouse, in folio, 1679.