 To speak of René Descartes’ contributions to the history of mathematics is to speak of his La Géométrie (1637), a short tract included with the anonymously published Discourse on Method. In La Géométrie, Descartes details a groundbreaking program for geometrical problem-solving—what he refers to as a “geometrical calculus” (calcul géométrique)—that rests on a distinctive approach to the relationship between algebra and geometry. Specifically, Descartes offers innovative algebraic techniques for analyzing geometrical problems, a novel way of understanding the connection between a curve’s construction and its algebraic equation, and an algebraic classification of curves that is based on the degree of the equations used to represent these curves.