Revisión de propustas de niveles de comprensión lectora

Asymptotics are a way of bridging perspectives. They allow the linking of different modal topologies. The move to a different qualitative region of the state space of the system corresponds to a change of perspective. If we use an explanatory idealisation, such as the thermodynamic limit in statistical mechanics, or the use of ray optics to explain rainbows, we enter a different region of the space of available parameters as it were, meaning that by taking such singular limits, we produce a different set of partitions and variables to connect modally. So when we take an asymptotic limit we change the “whats” as well as which of them depend upon which others.

We can define a new sense of mereological emergence based around explanation. Batterman has argued that asymptotics can provide a basis for a definition of non-mereological emergence: an emergent set of properties are those in the singular limit which cannot be recovered from the approach to that limit. I have sympathy with this view but I think it is too narrowly drawn and that some mereological aspect plays a role in emergence as well.

I think that the asymptotic definition could be subsumed under a wider definition of emergence in terms of explanatory emergence. The basic idea is that although we may be able to physically see a reduction basis from one level to another, we cannot collapse the modal topology from one level onto another. Of course, two different modal topologies at different levels cannot be in contradiction if they are both adequate explanations, but that does not mean that the modal topology of one should reduce to the other. Indeed the perspectivism argued for here illustrates why. To define a modal topology requires adopting a perspective, we should be able to provide bridging principles between perspectives but not necessarily reduce them to one another. That is, what-depends-upon-what at one level can be physically connected to another level but the modal connections need not be. The parts at one level reduce to the parts at another level but the modal connections between the parts at each level do not reduce, they merely have to be consistent. The two levels should not be in contradiction, and may present equivalent modal pictures in some respects, but each perspective may be able to capture different aspects of modal structure. The set of w- questions each is able to answer is different and this ability to distil modal information, that depends upon the perspective and hence the level of explanation, need not reduce.

So we can say in an emergent system what “emerges” is a set of variables and partitions of natural kinds that allows a modal topology to be defined. The elements in this level are physically connectible to the lower level but the same kinds of w-questions are not definable and modal aspects are only explicated at the higher level. An emergent property is then a variable that can be connected modally at one level but not at a reduced level.

By defending explanatory pluralism, especially across different levels we can defend a form of anti-reductionism at the level of explanation. We can still preserve the physical intuition that there is physical reduction possible. Chairs are made of atoms for instance, but what there is not is modal reduction: some counterfactuals about chairs cannot be expressed in the variable base of atoms. In reduction we have physical continuity but not explanatory continuity. In modelling terms, different fictional worlds need not collapse onto one another. Asymptotics reflects this, such analytic techniques provide a crucial role in bridging perspectives, by reducing the number of variables in a problem say, but it is this more general feature, shifting perspectives that allows a more general sense of emergence to be

articulated than only looking at asymptotics can provide.

The surrealism argued for here is entirely consistent with the notion of a cumulative knowledge base in science. Indeed it is deliberately intended to borrow aspects from Woodward's notion of science producing cumulative dependency relations and French & Ladyman's and others' structural realist contention that under theory change modal structure is preserved. When a new explanation is produced that extends the domain of a previous explanation the modal topologies must be consistent and bridgeable. Even though they need not reduce to one another they must agree on the observable consequences of that modal structure and the modal topologies must be connectible in some well defined sense. All of this, as Woodward argues, adds up to a cumulative set of modal relations that builds up over the history of science and narrows down the possibility space of how the world can appear to be. Now we must be clear that there is a qualitative difference between a quasi-explanation and a correspondence-explanation, just increasing the domain of a quasi-true explanation does not necessarily pin down how the actual correspondence true explanation must be. What greater and greater domains of quasi-explanations can do is narrow down the way the correspondence explanation must appear. So the true correspondence explanation featuring all the correspondence true ontology of the real world may be quite different from that hinted at by our quasi- explanations and their quasi-true ontologies, but we have still modally constrained the correspondence true ontology of the world. Whatever this true state is it must recover the appearance of the quasi-true explanations in their domain, it must allow us to see how the world looked as if these false ontologies were true.

This is in essence a structural surrealism, where the surrealistic modal structures of past theories are incorporated into new theories. This adding up of surrealist aspects does not necessarily get us closer to the correspondence-true ontology of the world, but it does limit how it can manifest itself at different explanatory levels, in different empirical domains and from different perspectives. So we build up a collection of modal topologies and perspectives, variables and their modal dependencies, and this menagerie of modalities must be preserved by any correspondence-true theory. When theories are shown not to be correspondence true and only quasi-true this is not a weakness of the scientific method, rather it is a strength, as only by finding the limits of the

domains in which quasi-explanations operate can we build the patchwork quilt of these domains that we must recover the appearance of, and by doing so hope to find our ultimate goal of realist correspondence explanations.