Para o Felipe.
[…]It was these reflections that recalled me from the particular studies of Arithmetic and Geometry to a general investigation of Mathematics, and thereupon I sought to determine what precisely was universally meant by that term, and why not only the above mentioned sciences, but also Astronomy, Music, Optics, Mechanics and several others are styled parts of Mathematics. Here indeed it is enough to look at the origin of the word; for since the nameMathematicsmeans exactly the same thing asscientific study,these other branches could, with as much right as Geometry itself, be called Mathematics. Yet we see that almost anyone who has had the slightest schooling, can easily distinguish what relates to Mathematics in any question from that which belongs to the other sciences. […] [p. 7]
RENÉ DESCARTES. Rule IV. p. 5–7. In: Rules for the direction of the Mind. Tradução de ELIZABETH S. HALDANE e G. R. T. ROSS. p. 1–40. In: WILLIAM BENTON. Descartes Spinoza. v. 31. In: ROBERT MAYNARD HUTCHINS. Great Books of the western world. Chicago, Londo, Toronto: Encyclopædia Britannica: 1952.