 After the known members of a class are colligated with the use of a conception, the second step of Whewell’s discoverers’ induction occurs: namely, the generalization of the shared property over the complete class, including its unknown members. Often, as Whewell admitted, this is a trivially simple procedure. Once Kepler supplied the conception of an ellipse to the observed members of the class of Mars’ positions, he generalized it to all members of the class, including those which were unknown (unobserved), to reach the conclusion that “all the points of Mars’ orbit lie on an ellipse with the sun at one focus.” He then performed a further generalization to reach his first law of planetary motion: “the orbits of all the planets lie on ellipses with the sun at one focus.”