 What Newton found was that these different kinds of phenomena—including circumjovial orbits, planetary orbits, as well as falling bodies—share an essential property, namely the same cause. What Newton did, in effect, was to subsume these individual “event kinds” into a more general natural kind comprised of sub-kinds sharing a kind essence, namely being caused by an inverse-square attractive force. Consilience of event kinds therefore results in causal unification. More specifically, it results in unification of natural kind categories based on a shared cause. Phenomena that constitute different event kinds, such as “planetary motion,” “tidal activity,” and “falling bodies,” were found by Newton to be members of a unified, more general kind, “phenomena caused to occur by an inverse-square attractive force of gravity” (or, “gravitational phenomena”). In such cases, according to Whewell, we learn that we have found a “vera causa,” or a “true cause,” i.e., a cause that really exists in nature, and whose effects are members of the same natural kind (see 1860a, p. 191). Moreover, by finding a cause shared by phenomena in different sub-kinds, we are able to colligate all the facts about these kinds into a more general causal law. Whewell claimed that “when the theory, by the concurrences of two indications … has included a new range of phenomena, we have, in fact, a new induction of a more general kind, to which the inductions formerly obtained are subordinate, as particular cases to a general population” (1858b, 96). He noted that consilience is the means by which we effect the successive generalization that constitutes the advancement of science (1847, II, 74). (For early discussions of consilience see Laudan 1971 and, especially, Hesse 1968 and Hesse 1971; for more on consilience and its relation to realism and natural kinds, see Snyder 2005 and Snyder 2006. On consilience and classification, see Quinn, 2017. For more on Whewell and scientific kinds, see Cowles 2016.)