 Thus the known points of the Martian orbit were colligated by Kepler using the conception of an elliptical curve. Often new discoveries are made, Whewell pointed out, not when new facts are discovered but when the appropriate conception is applied to the facts. In the case of Kepler’s discovery, the observed points of the orbit were known to Tycho Brahe, but only when Kepler applied the ellipse conception was the true path of the orbit discovered. Kepler was the first one to apply this conception to an orbital path in part because he had, in his mind, a very clear notion of the conception of an ellipse. This is important because the fundamental ideas and conceptions are provided by our minds, but they cannot be used in their innate form. Whewell explained that “the Ideas, the germs of them at least, were in the human mind before [experience]; but by the progress of scientific thought they are unfolded into clearness and distinctness” (1860a, 373). Whewell referred to this “unfolding” of ideas and conceptions as the “explication of conceptions.” Explication is a necessary precondition to discovery, and it consists in a partly empirical, partly rational process. Scientists first try to clarify and make explicit a conception in their minds, then attempt to apply it to the facts they have precisely examined, to determine whether the conception can colligate the facts into a law. If not, the scientist uses this experience to attempt a further refinement of the conception. Whewell claimed that a large part of the history of science is the “history of scientific ideas,” that is, the history of their explication and subsequent use as colligating concepts. Thus, in the case of Kepler’s use of the ellipse conception, Whewell noted that “to supply this conception, required a special preparation, and a special activity in the mind of the discoverer. … To discover such a connection, the mind must be conversant with certain relations of space, and with certain kinds of figures” (1849, 28–9).