Positivism and Logical Empiricism in the 19th century
The term positivism it derivates from August Comte . For its critical work, however, it can be considered Hume as the first great positivist. It showed the impossibility of deductive reasoning producing assertions of fact, since the deduction takes place and affects a second level, that of the concepts.
Positivism and Logical Empiricism
The development of the term positivism It has, however, been incessant. The basic affirmations of positivism are:
1) That all knowledge of the facts is based on "positive" data of the experience . -that reality exists, the opposite belief is called solipsism-.
2) That beyond the realm of facts there are logic and pure mathematics , recognized by Scottish empiricism and especially by Hume as belonging to "the relationship of ideas".
In a later stage of positivism the sciences thus defined acquire a purely formal character.
Mach (1838-1916)
Affirms that all factual knowledge consists of the conceptual organization and the elaboration of the data of the immediate experience. Theories and theoretical conceptions are only predictive tools.
In addition, theories can change, while observational facts maintain empirical regularities and constitute a firm (immutable) terrain for scientific reasoning to be grounded. Positivist philosophers radicalized empiricist anti-intellectualism, maintaining a radical utilitarian view of theories.
Avenarius (1843-1896)
He developed a biologically oriented theory of knowledge that influenced much of American pragmatism. Just as adaptation needs develop organs in organisms -Lamarckismo-, so knowledge develops theories for the prediction of future conditions.
The concept of cause it is explained according to the regularity observed in the sequence of events, or as a functional dependency between the observable variables. Causal relations are not necessary logically, they are only contingent and determined by observation and especially by experimentation and inductive generalization.
Many twentieth-century scientists, following the path opened by Mach, to which was added the influence of some "philosophers of mathematics" such as Whithead, Russell, Wittgenstein, Frege, etc., came together more or less unanimously around the positivist problem of the legitimacy of scientific theories.
Russell says: "Either we know something independently of experience, or else science is a chimera."
Some philosophers of science, known as the group of Circle of Vienna, established the principles of logical empiricism:
1. First of all, they believed that the logical structure of some sciences could be specified without taking into account their contents .
2. Second established the principle of verifiability , according to which the meaning of a proposition must be established through experience and observation. In this way ethics, metaphysics, religion and aesthetics were beyond scientific consideration.
3. Third, they proposed a unified doctrine of science , considering that there were no fundamental differences between physics and the biological sciences, or between natural sciences and social sciences. The Circle of Vienna reached its maximum activity during the period before the second war.
Conventionalists
Another group of inductivists, of different orientation -including those of influence Marxist , which is known as school of frankfurt - are the Conventionalists , who maintain that the main discoveries of science are, fundamentally, inventions of new and simpler classification systems.
The fundamental features of classical conventionalism - Poincaré - are, therefore, decision and simplicity. They are also, of course, anti-realistic. In terms of Karl Popper (1959, page 79):
"The source of conventional philosophy seems to be amazement at the austere and beautiful simplicity of the world as revealed in the laws of physics. The conventionalists (...) treat this simplicity as our own creation ... (Nature is not simple), only the "laws of Nature" are; and these, conventionalists maintain, are our creations and inventions, our arbitrary decisions and conventions. "
Wittgenstein and Popper
This form of Logical Empiricism was soon opposed by other forms of thought: Wittgenstein , also a positivist, faces, however, the verificationist positions of the Vienna Circle.
Wittgenstein argues that verification is useless. What language can communicate what "shows" is an image of the world. For Wittgenstein's logical heirloom positivism logical formulas say nothing about the meanings of propositions, but merely show the connection between the meanings of propositions.
The fundamental answer will come from the falsificationist theory of Popper , which supports the impossibility of an inductive probability with the following argument:
"In a universe that contains an infinite number of distinguishable things or spatiotemporal regions, the probability of any universal law (not tautological) will be equal to zero." This means that the increase in content of an affirmation decreases its probability, and vice versa. (+ content = - probability).
To solve this dilemma, he proposes that one should try to falsify the theory, seeking the demonstration of the refutation or counter-example. In addition, it proposes a purely deductivist methodology, in fact a negative hypothetical-deductive or falsificationist one.
As a reaction to this approach arise a number of theorists who criticize logical positivism-Kuhn, Toulmin, Lakatos and even Feyerabend-although they differ about the nature of the rationality exhibited by scientific change. They defend notions like scientific revolution, in opposition to progress -Kuhn-, or the intervention of irrational processes in science -Feyerabend's anarchist approach-.
The heirs of Popper are now grouped under the Critical rationalism , in a last effort to save science, theory and the notion of "scientific progress", which they do not without some difficulty, proposing as alternatives, among others, the establishment of rival Research Programs, defined by their heuristics, and that compete with each other.
The difficulties of the logical models applied to the methodology of Science, therefore, could be summarized as follows:
The induction of the theory, from particular data, was already clearly not justified. A deductivist theory will achieve nothing because there are no sure general principles from which deduction can be derived. A falsificationist vision is inadequate because it does not reflect scientific practice - scientists do not operate like this, abandoning theories, when they present anomalies.The result seems to be a skepticism generalized in terms of the possibility of distinguishing between valid theories and ad hoc theories, so it is usually ended by appealing to history, that is, the passage of time as the only safe method, or at least with certain guarantees, to judge the adequacy of the models - another form of conventionalism.
