Philosophy of Science : Help or Hindrance ? 1

—Scientists routinely employ metatheoretic principles, explicit discussion of which typically occurs in times of intense controversy, theoretical crisis, scientific revolution, and entry into a new domain. The writings of philosophers, including their disagreements, are often helpful in such circumstances. Whether knowledge of formal metatheory helps us in doing “normal science” is researchable. Much scientific thinking is of poor quality, and it could be improved by explicit metatheoretical education. Clinical practice and training programs should emphasize rational skepticism, respect for evidence, objectivity, and quantitative thinking. Because the relation between principles and success is probabilistic, metatheoretical research should implement the case study method by formal actuarial procedures. The subtitle of this article may suggest that working scientists, whether chemists or psychologists, can avoid philosophizing; but we cannot. Scientists philosophize willy-nilly, whether or not they label it as such. Consider a typical article in an experimental journal. After an introductory section describing the scientific problem, a “methods” section describes what was done; a “results” section reports observations and statistical or graphical summaries of them; mathematical derivations may be presented. The terms in these sections designate objects, properties, and events of the subject-matter domain. They speak of rats pressing levers, schizophrenics sorting MMPI items, college students reporting perceptions, and theoretical entities employed to “explain” these things. The logician calls such expressions object language because they are about the objects—observed or inferred—of which the science treats. Then comes the “discussion” section, where a different sort of statement appears and often predominates. Here, the scientist speaks about the object-language statements, their meaning and their logical relations, especially the probative relations between the theoretical and observational statements. Logicians call this metalanguage, since its referents are not the physical objects of the domain but the scientist’s statements. The tipoff to metalinguistic discourse is the recurrence of such terms as ‘prove,’ ‘infer,’ ‘valid,’ ‘fallacious,’ ‘follows from,’ ‘is consistent with,’ ‘casts doubt on,’ ‘assumes,’ ‘evidence for,’ ‘contradicts,’ ‘denotes,’ ‘defines,’ ‘true,’ and ‘false.’ The term ‘probable’ is object-linguistic when it denotes a statistical relative frequency, but it is metalinguistic when it characterizes the relation of evidentiary support. The 1 Invited address delivered at the Fourth Annual Convention of the American Psychological Society, San Diego, California, June 20-22, 1992.