The key question, however, is whether our intuitive notion (or notions) of unification can be made more precise in a way that allows us to recover the features that we think that good explanations should possess.
More generally, it casts doubt on Kitcher's contention that one can begin with the notion of explanatory unification, understood in a way that does not presuppose causal notions, and use it to derive the content of causal judgments.
Instead, Kitcher proposes to begin with the notion of explanatory unification, characterized in terms of constraints on deductive systemizations, where these constraints can be specified in a quite general way that is independent of causal or counterfactual notions, and then show how the causal claims we accept derive from our efforts at unification.
We extend the notion of anti-unification to cover equational theories and present a method based on regular tree grammars to compute a finite representation of E-generalization sets.
Beforehand, the notions of national unification and expansion had been indivisible: just 15 years prior, the United States defeated Mexico in a bloody war that brought vast territories under occupation and destroyed the delicate balance between slave and free states.
Held together only by the idea of unification, their notions of how to achieve this did not include specific plans but instead rested on the nebulous idea that the Volk (the people), if properly educated, would bring about unification on their own.
In anti-reductionist quarters, models of unification without reduction have readily appeared: for instance, the notion of interfield theories (Darden and Maull 1977; Darden 2006).
Even Nishida's early work, An Inquiry Into the Good, had spoken of God in a way that undermined the notion of a transcendent being outside the world; it conceived of God as the infinite activity of unification at work behind the articulations of spirit and nature out of pure experience.
