 The first two laws were published initially in AN (1609), although it is known that Kepler had arrived at these results much earlier. His first law establishes that the orbit of a planet is an ellipse with the Sun in one of the foci (see Figure 2). According to the second law, the radius vector from the Sun to a planet P sweeps out equal areas, for instance \(SP_1P_2\) and \(SP_3P_4\), in equal times. The planet P is therefore faster at perihelion, where it is closer to the Sun, and slower at aphelion, where it is farther from the Sun. In accordance with his dynamical approach, Kepler first found the second law and, then, as a further result because of the effect produced by the supposed force, the elliptical path of the planets (for the two first planetary laws see especially Aiton 1973, 1975a, Davis 1992a–e, and 1998a; Donahue 1994; Wilson 1968 and 1972; for Kepler’s system of conics in connection with his optics see the recent study by Del Centina, 2016).