Abstract
Philosophical critique of scientific levels or candidate level-systems often blends into critique of the activity of leveling. Here I defend leveling, the activity, with no commitment to any given scientific system of levels or the notion that within a given scientific system there is necessarily one best way to level that system. After looking at instances of leveling across the life sciences, I conclude that to level something is to either conceive of that thing in a more inclusive context than that of just itself, or conceive of that thing as providing, for certain other things, a more inclusive context than just what is provided by each of those things by themselves. I also notice there are different kinds of context in which one can level: when leveling, the varying context might be spatial, temporal, compositional, conceptual, detail- or information-oriented, functional, or more. We like to level in lots of different ways, and to level lots of different things. Yet I still think it possible to defend a concept of leveling which respects the different and diverse outcomes of this conceptually coherent leveling activity. My primary aim is to make sense of different kinds of level talk—all of which rely on a concept of leveling, and seem worth saving (to me): for instance, talk of wholes being on a different compositional level than their parts; talk of first-order and second-order sentences being on different referential levels from one another; talk of cellular organelles, cells, and organs being on different spatial levels; talk of ages, epochs, periods, and eras being at different temporal levels; talk of tokens and types, instantiations and abstractions, thick and thin descriptions all being on different conceptual levels; and more. Secondarily, I hope to successfully relate leveling in the context of abstraction to leveling in these other contexts. When we conceive of a thing in a more inclusive context than just itself, we generally talk of having gone up a level. When we conceive of a thing as providing, for certain other things, a more inclusive context, we generally talk of having gone down a level. But “up” and “down” are just relational signs that indicate movement in opposing directions from one another. Moving up to a higher level in the sense of abstraction is often more inclusive in the sense of number of things included, but less inclusive in the sense of amount known about or ascribable to each thing included. Moving down to a lower level in the sense of abstraction is often less inclusive in terms of the number of things rightfully included in that new context but more inclusive in the sense of details attributable to each member of the set. This is a case where the relevant signs might flip, depending on what context or dimension is being emphasized, because there is often a negative correlation between amount of detail and extent of abstraction.
