The Overall Perspective: Reductionist or Non-reductionist?
The central question addressed in this work is how far the psycholinguistic approach takes us in explaining language. The overall conclusion is that it takes us quite a long way. Of course, this does not mean that the psycholinguistic approach is omnipotent: language cannot be reduced to psychology, in much the same way as phonology cannot be reduced to phonetics. This is because language is more than a psychological phenomenon. All the other facets discussed in Chapter 2 also have a role in this game. Unfortunately, it is not known how far these non-psychological approaches take us, because their impact upon the structure of language has not yet been investigated systematically and comprehensively. We are even more in the dark as to the multifarious interactions that may exist among the various dimensions of language. There are two reasons why relatively little explanatory work has been forthcoming. For one thing, the relevant disciplines have not progressed to the point where a direct and systematic link with language can be established. The paradigm case exemplifying this state of affairs is the neurosciences. For another, researchers in the disciplines in question have been intent on setting themselves off against the philosophy of autonomous linguistics; their attempts to establish their relative independence from formal linguistics have distracted their attention from issues of language structure. Therefore, the results of their research are often not directly transferable to the issues that are of major concern in the present study.
To put this work in a wider perspective, a vision of language and linguistics will be outlined which may serve as a research programme as well as a metatheory. Let us embark upon the following Gedankenexperiment. Suppose all disciplines have advanced to such a stage that it is possible to carry through a large-scale investigation of the impact that all external approaches make upon language structure. The next step would be an examination of the effects that the approaches produce, not in isolation but in combination. After this work has been completed, one would be in a position to reliably assess the contributions of each discipline individually and all disciplines collectively to the explanation of language structure. What might be the outcome of this assessment? Either all these external approaches provide a comprehensive account of language structure or there remains a significant portion of linguistic patterns that cannot be so explained. It goes without saying that there is currently no rational basis for anticipating which alternative will eventually turn out to be the correct one.