Positivism and Logical Empiricism in the 19th century.

Review of the contributions of empiricist currents and logical positivism to psychology.

The term positivism derives from August Comte. For his critical work, however, it is possible to consider Hume as the first great positivist. He showed the impossibility of deductive reasoning to produce assertions of fact, since deduction takes place and affects a second level, that of concepts.

Positivism and Logical Empiricism

The development of the term positivism has, however, been incessant. The basic assertions of positivism are:

1) That all knowledge of facts is based on "positive" data of experience.. -That reality exists; the contrary belief is called solipsism.

2) That beyond the realm of facts are logic and pure mathematics. are logic and pure mathematicsThe sciences, recognized by Scottish empiricism and especially by Hume as belonging to "the relation of ideas".

At a later stage of positivism the sciences thus defined acquire a purely formal character.

Mach (1838-1916)

He affirms that all factual knowledge consists of the conceptual organization and conceptual organization and elaboration of the data of immediate experience. Theories and theoretical conceptions are only instruments of prediction.

Moreover, theories can change, while observational facts maintain empirical regularities and constitute a firm (immutable) ground on which scientific reasoning can be grounded. Positivist philosophers radicalized empiricist anti-intellectualism, maintaining a radical utilitarian view of theories.

Avenarius (1843-1896)

Elaborated a biologically oriented theory of knowledge that influenced much of American pragmatism. Just as adaptive needs develop organs in organisms -Lamarckism-, so knowledge develops theories for the prediction of future conditions.

The concept of cause is explained in terms of the regularity observed in the succession of facts, or as functional dependence between observable variables.or as functional dependence between observable variables. Causal relationships are not logically necessary, they are only contingent and determined by observation and especially by experimentation and inductive generalization -Hume-.

Many scientists of the twentieth century, following the path opened by Mach, to which was added the influence of some "philosophers of mathematics" such as Whithead, Russell, Wittgenstein, Frege, etc., more or less unanimously rallied around the positivist problem of the legitimacy of scientific theories.

Russell states, "Either we know something independently of experience, or science is a chimera."

Some philosophers of science, known as the group of the Vienna Circle, established the principles of logical empiricism:

1. First, they believed that the logical structure of some sciences could be specified without taking into account their contents..

2. Secondly, they they established the principle of verifiabilitySecondly, they established the principle of verifiability, according to which the meaning of a proposition must be established by experience and observation. In this way ethics, metaphysics, religion and aesthetics were left out of any scientific consideration.

3. Thirdly, they proposed a unified doctrine of science.Third, they proposed a unified doctrine of science, considering that there were no fundamental differences between physics and the Biological sciences, or between the natural sciences and the social sciences. The Vienna Circle reached its peak of activity during the period before the Second World War.

Conventionalists

Another group of inductivists, of different orientation - among them those with Marxist Marxist influencewho are known as the Franckfurt school Franckfurt school- are the Conventionalistswho hold that the main discoveries of science are, fundamentally, inventions of new and simpler systems of classification.

The fundamental features of classical conventionalism - Poincaré - are, therefore, decisiveness and simplicity. They are also, of course, anti-realist. In terms of Karl Popper (1959, pg. 79):

"The source of conventionalist 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 simple; and these, the conventionalists maintain, are our own creations and inventions, our own arbitrary decisions and conventions".

Wittgenstein and Popper

This form of Logical Empiricism was soon opposed by other forms of thought: WittgensteinWittgenstein, also a positivist, confronts, however, the verificationist positions of the Vienna Circle.

Wittgenstein argues that verification is useless. What language can communicate it "shows", it is an image of the world. For the logical positivism inherited from Wittgenstein, logical formulas do not say anything about the meanings of propositions, but merely show the connection between the meanings of propositions.

The fundamental reply will come from Popper's falsificationist theory. Popperwhich supports the impossibility of an inductive probability with the following argument:

"In a universe containing an infinite number of distinguishable things or spatio-temporal regions, the probability of any universal (non-tautological) law will be equal to zero." This means that with increasing content of a statement 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 counterexample. Moreover, he proposes a purely deductivist methodology, actually negative hypothetico-deductive or falsificationist.

In reaction to this approach, a number of theorists 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 such as scientific revolution, as opposed to progress -Kuhn-, or the intervention of irrational processes in science -Feyerabend's anarchist approach-.

Popper's heirs are now grouped together under the name of Critical RationalismThey do so not without some difficulty, proposing as alternatives, among others, the establishment of rival Research Programs, defined by their heuristics, and competing with each other.

The difficulties of logical models applied to the methodology of Science, therefore, could be summarized as follows:

The induction of theory, from particular data, was clearly no longer justified. A deductivist theory will achieve nothing because there are no certain general principles from which deduction can be derived. A falsificationist view is inadequate because it does not reflect scientific practice - scientists do not operate in this way, abandoning theories when they present anomalies.

The result seems to be a skepticism The result seems to be a widespread skepticism as to the possibility of distinguishing between valid theories and ad hoc theories, so that one usually ends up appealing to history, that is, to the passage of time as the only sure method, or at least with certain guarantees, to judge the adequacy of models -another form of conventionalism-.