Page 292 - Encyclopedia of Philosophy of Language

Language and Logic
intheworkofAristotle(d.322BC),logicwentthrough a period of general stagnation relieved only by rela- tively isolated contributions until the late nineteenth and early twentieth centuries, when logic was trans- formed by discoveries which eclipsed even the bril- liance of Aristotle's work. This article will give an outline of this history, particularly as it bears on topics relating to language and linguistics.
1. The Study of Logic and Related Subjects
Perhaps the fact that a subject should begin well and then remain in the shadows for a long time will not seem so surprising. After all, there are fashions in the intellectual world as in any other. However, what deepens the mystery of the history of logic is that its period of stagnation did not coincide with one of neglect. On the contrary, for all the centuries it remained largely unchanged, it continued to play a special and prominent role in the liberal education offered in every place of learning. If there is one species of textbook in the university tradition which has at once the longest and most curious history it is that of the logic text. The form may vary from period to period, but, if one surveyed what counted as logic texts from the period after Aristotle to the present day, one would see the point about the history of logic illustrated in a most graphic way. There are certainly thousands of different exemplars of the type 'logic textbook,' and they were used continuously in the educational tradition of the west. Yet there was a
period of over a thousand years in this tradition when the formal logical content of these textbooks changed very little. The difference between the logic texts of the early medieval period and the middle nineteenth century would be real but of no real significance in comparison to the change which has taken place since then. It is a simple fact that the standard present text in formal logic contains very little of what would have figured centrally in the text of about a hundred years before.
Here something should be added to soften the stark picture just painted. As was noted, that part of logic which remained such an unchanged part of the syl- labus for so long was formal logic. But there are other aspects of the subject which are woven around the formal core. Logic began as the study of inference and validity, and through the work of Aristotle the formal study of inference was born. This formal study (known best under the heading of the 'syllogism,' details of which follow in Sect. 3) was the relatively unchanging core of the subject from after Aristotle until the begin- ning of the present century. Around this core there revolved a great many topics which nowadays would be classified under the headings 'philosophy of logic' and 'philosophy of language.' Here are found ques- tions about the nature of premises and conclusions of arguments, whether they are sentences, thoughts, propositions distinct from either of these, as well as
questions about concepts ranging from those about individuals and species to those about modality (notions such as possibility) and logical form (notions such as universality, particularity, conditionally and disjunction). In many and subtle ways there was a gradual growth in wisdom about this latter subject matter—the philosophies of logic and language—and this is especially evident when one goes back to medi- eval texts with the hindsight gained from modern discussions. However, it can seem surprising that the advances made in these areas had so little impact on the development of formal logic itself: time and again one sees suggestions here and there in the history of the subject where one feels that 'if only this suggestion were followed through and applied to formal methods, a large part of what now goes on in logic would have developed hundreds of years earlier.'
The reason for this curious situation is particularly important in the present context. For what has largely made the difference necessary for the revolutionary changes in logic in the twentieth century has been a change in the framework within which the subject is studied, and that change has brought about a situation in which formal logic is a crucial part, not merely of the study of inference, but in the study of language and linguistics. Essentially what seems to have happened is that the formal study of inference, and the related unsystematic studies of philosophy of language and logic, existed side-by-side, but without any coherent metatheory to unite them. Since the 1890s, and especially due to the work of Gottlob Frege, a fun- damentally different notion of the role of formal logic in the context of philosophy of logic and language has arisen. Along with this change have come revo- lutionary changes in formal methods themselves. But what is most important in the present context is that the changed perspective on logic has made it a fun- damental aspect of the study of natural language. Of
course, the study of inference still remains the starting point for logic, and important branches of the subject have very little directly to do with natural language, but it is now seen that in studying inference one is also systematically studying the rich linguistic structure which is expressed in natural languages. For, in their myriad different ways, all natural languages are cap- able of expressing thoughts that it is the business of logic to capture in precise form. Indeed, it has even been thought that the formal languages of logic give the deep structure of the thoughts expressed in natural languages. However,whetheror not logical languages have this exact role, there is no doubt that the study of logic now plays almost as central a part in linguistics as it does in philosophy itself.
2. Logic Before Aristotle
The study of inference could have begun almost any- where, since the use of argument and reason is as widespread as humanity itself. Thus, one can only
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