On What We Know We Don’t Know - Stanford University

1 On what We know We Don't know Explanation, Theory, Linguistics, and How Questions Shape Them On what We know We Don't know Explanation, Theory, Linguistics, and How Questions Shape Them Sylvain Bromberger The University of Center for the Study of Chicago Press Language and Information Chicago and London Stanford The University of Chicago Press, Chicago 60637. The University of Chicago Press, Ltd., London c 1992 by the Center for the Study of Language and Information Leland Stanford Junior University All rights reserved. Published 1992. Printed in the United States of America 99 98 97 96 95 94 93 92 54321.

2 CIP data and other information appear at the end of the book To the memory of Aristides de Sousa Mendes Portuguese Consul in Bordeaux in June 1940. with gratitude Contents Introduction 1. 1 An Approach to Explanation 18. 2 A Theory about the Theory of Theory and about the Theory of Theories 52. 3 Why-Questions 75. 4 Questions 101. 5 Science and the Forms of Ignorance 112. 6 Rational Ignorance 128. 7 what We Don't know When We Don't know Why 145. 8 Types and Tokens in Linguistics 170. 9 The Ontology of Phonology 209. with Morris Halle Bibliography 229. vii Introduction The nine papers in this book cover topics as diverse as the nature of explanation, the ambiguity of the word theory, the varieties of ig- norance, the limits of rationality in the choice of questions, and the ontology of linguistics.

3 Each is self-contained and can be read inde- pendently of the others. They are arranged essentially unchanged in the order in which they chronologically appeared. The book as a whole can thus be approached simply as a collection of papers that were previously scattered across many publications and are now as- sembled under one cover for convenience. However, the book can also be approached as a collection of pa- pers that belong naturally together by virtue of a common idea and a common agenda based on that idea. Philosophers have always recognized that scientific progress consists in more than successive additions to a stock of truths and highly confirmed propositions.

4 But what that more comes to has turned out to be surprisingly controversial and elusive. The idea common to these papers is that the more will be found in the truism that science seeks answers to questions. The common agenda then is simply to examine with some care what such seeking involves. We find ourselves, as individuals and as communities, willy-nilly cast in a world not of our own making, in which we want to survive, if possible to thrive, and whose features we want to understand. We start out with little prior information about that world, but we are endowed with the ability to come to know that there are things about it that we don't know , that is, with the ability to formulate and to entertain questions whose answers we know we do not know .

5 It is an enormously complex ability derived from many auxiliary 1. 2 On what We know We Don't know abilities. And it induces the wish to know the answer to some of these questions. Scientific research represents our most reasonable and responsible way of trying to satisfy that wish. That is its most tenable defining goal, and not, as others have held, the construction of doctrines that can be recast as interpreted formal systems, or the achievement of intellectual economy, or the refutation of conjectures, or the solution of puzzles, or the provision of means for practical suc- cess, or the contrivance of communal consensus, or the domination of certain institutions, or the elaboration of ever more encompass- ing systems, or the making of worlds.

6 Those sorts of achievements represent at best accidental objectives. However, in seeking its goal science repeatedly runs into difficul- ties. Many of these difficulties are physical in nature and call for the design of new and more powerful instruments. Others are psy- chological and call for the invention of devices that supplement our memory and our computational powers. Still others, and those are the ones that are relevant here, are intellectual and pertain to our ability to conceive, formulate, consider, connect, and assess ques- tions, and to our ability to conceive, formulate, consider, connect, and assess answers.

7 These sorts of difficulties often call for inspira- tion and creative intelligence. Careful observation and description are not enough. The idea linking these papers can thus be put more explicitly. It is that this more that scientific endeavors add to truths and warranted beliefs consists of insights through which inspiration and creative intelligence manage to overcome such intellectual difficulties. And the agenda is to specify the character of these insights. In the rest of this introduction I will briefly describe the content of each paper. I will first describe the specific topic to which it is addressed for readers who look at it simply as a self-contained paper.

8 I will then describe how it fits in the overall agenda when that is not obvious from the nature of the topic. An Approach to Explanation belongs to the vast philosophic literature that seeks to analyze the notion of explanation. what is at stake can best be appreciated by noting an odd disagreement among philosophers of science. Some, Pierre Duhem most notably among them, hold that empirical science does not and cannot provide expla- nations. Others, and that includes most contemporary philosophers of science, hold that, on the contrary, science can and does provide Introduction 3. explanations.

9 All sides agree that the notion of explanation connotes norms and desiderata, and all sides also agree that the question is whether those norms and desiderata are compatible with the primary positivistic demands for empirical evidence, inductive justification, consistency, generality, productivity, etc. The sides differ on what the connoted norms and desiderata come to, and so they reach differ- ent conclusions about their legitimacy. what is at stake, then, goes beyond what the notion of explanation (or the word that expresses it) connotes and affects our consciousness of scientific desiderata and norms, and our awareness of what science can or cannot aspire to achieve.

10 I will not summarize my own analysis of these connotations here, since the whole paper is near at hand, but I can prepare the ground with a few remarks about its general character. The paper was written under the influence of so-called ordinary language philosophy. It therefore focuses unashamedly on our use of the verb to explain and of its nominalization explanation on the obvious ground that the most direct way to find out what the notion of explanation connotes is to examine how we apply the words explain and explanation. The analysis starts from the observation of two facts: first, the purely grammatical fact that the verb to explain and its cognate ex- planation of admit interrogative sentences (in indirect speech form, , without so-called wh-aux inversion) as their complements; sec- ond, the nongrammatical fact that though they admit a wide range of questions as complement, they normally exclude some.