Resumen:
Some main problems of Philosophy of Science, namely concepts, hypothesis, laws, theories, cause, explanation and prediction, are examined in the article, according to the tradition of Logical Empiricism. The author exemplifies the discussion by refering to the literature on Polítical Development. A language has two kinds of terms: logical and descriptive. The descriptive or extra-Iogical terms may be either proper names, or property words. The latter are also caIled concepts. Concepts refer to properties (or relations), which are exemplified by facts and events in the world. Concepts may be either primitive, or defined. The meaning of defined concepts is introduced by definitions, through the specification of the properties to which the concept refers. Definitions are conventions: they are not discovered, but created. They should be both empirically precise, and theoretically significant. Concepts are created in order to be used in hypotheses, so that concept formation and theory building cannot be treated separately. Lack of precision in definitions has lead authors to search for "indicators·'. However, once concepts are precisely defined, there is no need to deal with "indicators": ali one has to do is to see whether the properties specified in the definition are exemplified or not by facts and events in the world. The search for "indicators" simply reflects the need of properly stated definitions. Hypothesis are generalized propositions of the kind "if ... then", which relate two or more concepts. Since they are expressed by synthetic sentences, they are true or false according to the way the world is. Depending on the quality and the quantity of the available direct and indirect evidence, a hypothesis can be accepted beyond reasonable doubts. If accepted, it is called a law. Causal laws are special kinds of law: they specify, asymetrically, a temporal sequence between its concepts. A theory is a deductively related body of laws.The explanation of a fact or event consists in subsuming it to a law, or laws. Likewise, laws of low leveI of generalization are explained when subsumed to laws of higher leveI of generalization. The logical strncture of prediction is not basically different from that of explanation, especially when universal Iaws are involved. The search for causal laws, and for theories that integrate them, is the most important aim of the empirical sciences, for if we know the causes and effects of phenomena, then, at least in principIe, it is possible to control them. Finaly, the author calls the attention to the difference between the task of logical reconstruction of science, and the task of construction of science. The former may be helpful to the latter, but it should be used with care, so that it does not create obstacles to the developrnent of science.
Descripción:
"Gostaria de deixar claro que este trabalho, com algumas exceções (sobretudo a
discussão sobre indicadores). é muito mais um esforço de síntese, do que de criação.
Além dos autores citados na bibliografia, gostaria de reconhecer meus débitos para
com W. Kelley, professor da Universidade de Chicago. Também os professores Jorge
Balan e Hugo Amaral, ambos da Universidade Federal de Minas Gerais. ofereceram
criticas valiosas à versão original do texto. Entretanto, nenhum deles, sobretudo os
dois últimos, deve ser identificado com a posição metodológica aqui defendida."