While positivism was the most defining philosophy of science in the 20th century, it is now considered dead and has primarily been used as an oppositional term, a caricature, and a strawman easily dismissed and used for propping up ideas. Despite the derision of positivism, especially logical positivism, their ideas and influence are still heavily prevalent in our modern philosophy of science and have helped shape fields like logic and the humanities. Which permits the question: Was its obituary written too hastily?
Positivism: Towards Modern Science
Positivism, as was originally originated by Auguste Comte, who was heavily inspired by his teacher Saint-Simon, was essentially the first step towards a modern philosophy of science—yet positivism itself at the time was more of a movement for the betterment of society.
Comte’s ideas can be identified in one of his sayings: “Love as a principle and order as the basis; Progress as the goal” (Comte in Système de politique positive, 1841-45, p. 19). He sought to create a methodology for rational thought by taking a historical perspective and wished to accelerate the shift of science to becoming entirely secular, from previously being partially operated by religion.
Comte saw scientific (positive, in Comte’s terms) knowledge as the final evolution in a society’s knowledge, building on top of theological and subsequent metaphysical knowledge. This is why Comte also wanted to shift out metaphysical knowledge, which he saw as a remnant of the Enlightenment and its rationalism, hindering progress.
Comte believed in a hierarchy of science, in which the less complex and more general sciences, like physics, are at the top, with the more complex, more specific, and more dependent on other sciences, like sociology, at the bottom. This hierarchy makes it so that the higher ones are more determined.
Hume’s Influence on the Development of Positivism
The positivist philosophy was heavily inspired by Hume’s empiricism and scientific anti-realism. Knowledge regarding matters of fact could only be based on positive observational data or proof of logic. Theoretical entities and laws, like electrons and gravity, which are not observable, are mere instruments of prediction.
This stance can naturally lend itself to an anti-metaphysical view. As Hume put it:
“If we take in our hand any volume; of divinity or school metaphysics, for instance; let us ask, Does it contain any abstract reasoning concerning quantity or number? No. Does it contain any experimental reasoning concerning matter of fact and existence? No. Commit it then to the flames: for it can contain nothing but sophistry and illusion.”
Hume, Enquiry Concerning Human Understanding, 1748, sect. 12, pt 3
Logical Positivism: Language and Logic
The subsequent big movement in the philosophy of science formed under the name logical positivism, or logical empiricism, as the practitioners themselves called it—as they didn’t want the direct association with the previous movement and the baggage it brought. Yet their initial philosophical beliefs were a direct continuation of it and built upon the work of later positivists like Mach and Avernarius.
The logical positivism movement was divided into two groups: the Vienna Circle and the Berlin Society. The Vienna Circle was primarily headed by Rudolf Carnap, Otto Neurath, Hans Hahn, and Moritz Schlick, while the Berlin one was headed by Hans Reichenbach.
Logical positivism was similar to positivism in that it was more of a movement than a philosophical doctrine, and they even shared the explicitness of trying to improve society. They wanted to unify the sciences, which they sought through a unity of scientific language, and to remove unverifiable claims that were starting to permeate society—even in the spheres of science.
The positivist movement was subsequently overshadowed by its successor; it is not uncommon for people to misconstrue positivism as the latter movement.
Unifying Science Through Language
Logical positivism differentiated itself from its predecessor by using the philosophy of language, meaning, and logic to achieve its goals.
They saw a possibility in logic and mathematics as a universal language that could be used to unify science. By formulating theories and laws in this precise language, they hoped to eliminate ambiguity and ensure rigor across scientific disciplines and philosophy.
The ideas of Wittgenstein inspired this notion in the Tractatus and Russell through his extensive work in logic. Taken together, it insinuated that language’s structure mirrors the world’s logical structure and that mathematics could be reduced to logic. Mathematical truths could be accounted for by logic, as opposed to metaphysics. This would enable a link between mathematical truths and the world, a link very attractive to empiricists.
Continuing from the work laid out by Russell, logical positivism built upon Hume’s fork on the analytic-synthetic distinction of the truth of statements, modifying it so the truth of statements can be ascertained by virtue of their own meaning and/or logical structure or through empirical observation.
Logical positivists hoped that logic could make scientific and philosophical language unambiguous and universal.
There was a need for a method to distinguish between meaningful and meaningless statements in science and philosophy. This was attempted through the verification principle, first proposed by Wittgenstein. This principle holds that only that which can be verified to be analytical or synthetical is scientifically meaningful. This left statements of metaphysics, ethics, and aesthetics scientifically meaningless.
However, it is important to note that meaningful, in this case, means having truth value. That which is meaningless in terms of scientific truth need not be meaningless overall for us.
Questioning the Logic of Logical Positivism
Logical Positivism, initially a promising movement aimed at establishing a universal language for science based on logic and mathematics, quickly encountered significant challenges that threatened to undermine its foundations.
Gödel’s incompleteness theorems and Tarski’s undefinability theorem revealed the limitations of formal language, even when grounded in logic or mathematics. These theorems raised doubts about creating a complete and consistent system for expressing all scientific truths.
The concept of verificationism, central to logical positivism, also faced scrutiny. The verifiability paradox highlighted the self-contradictory nature of verificationism itself, as its criteria could not verify it. If a meaningful sentence had to be verified analytically or through observation, then the verification principle fell outside this definition.
Furthermore, Quine’s critique in “Two Dogmas of Empiricism” questioned the fundamental distinction between analytic and synthetic truths and the necessity of analyticity altogether. Quine proposed a more holistic view of science, where analytic truths are intertwined with empirical beliefs and cannot be isolated. He also argued against reducing meaning to experience, suggesting that meaning is derived from the interconnected web of beliefs and concepts.
These challenges collectively weakened the foundations of logical positivism and led to its decline as a dominant philosophical movement. While its initial ambitions were bold and promising, the limitations of formal language, the self-contradictory nature of verificationism, and the critique of analyticity posed formidable obstacles that ultimately proved insurmountable.
Carnaps Response
In fact, these findings would be the death of Logical Positivism as a cohesive movement, though since it wasn’t a doctrine, the ideas could be further developed.
The logician Rudolf Carnap was the main architect of this development. He addressed the limitations exposed by Gödel’s incompleteness theorem by modifying the analytic criterion and shifting focus from syntax to semantics. By introducing concepts like truth and meaning, Carnap sought to circumvent the limitations of formal languages.
Carnap’s Principle of Tolerance offered a pragmatic solution to the verification problem. He moved away from the idea of a single, universal scientific language and proposed a framework where different scientific inquiries could employ different languages and logic as long as they adhered to the scientific method. This flexible approach allowed for a greater diversity of scientific expression while maintaining the rigor of empirical inquiry.
Carnap also began to explore confirmationism as an alternative to strict verificationism, recognizing that scientific claims often rely on probabilistic evidence rather than absolute proof. He also moved away from definitional reducibility, acknowledging the complexity and interconnectedness of scientific concepts.
While Carnap’s work retained a strong positivist emphasis on empiricism, his engagement with the philosophy of language led him to depart significantly from the original framing of logical positivism. However, this shift should not be seen as a failure. Instead, it reflects the dynamic nature of philosophical inquiry and the need to adapt to new challenges and discoveries.
As Carnap demonstrated, logical positivism was never a rigid doctrine but rather a collaborative effort by thinkers with shared goals and foundations. His pragmatic approach exemplified the spirit of inquiry that characterized the movement, and his work ultimately helped pave the way for the next stage of philosophy of science.
Postpositivism: Incorporating Criticisms
Carnap’s progress is a single thread of the switch that occurred in the philosophy of science built upon the critique of logical positivism. Postpositivism, as is implied, is largely an evolution of the core principles of both positivisms. This evolution was built upon the criticisms, yet the core principles and ideals remained largely unchanged. What was done was the loosening of the constraints and the realization of the limits of rationality, empiricism, and how subjectivity and fallibility impact science.
These realizations come from several sources, making them largely unavoidable. The most prominent example is Kuhn and his revolutionary philosophy of science, which in several ways caused problems for positivism. His idea of theory-laden observations means that the underlying theories that someone holds will influence what they observe. This makes the criteria of pure objective observation of empiricism impossible and, subsequently, that of a universal scientific language.
This led postpositivism to take the stance of a more pluralistic science, accepting approximate truth or it being mediated through theories. It also allowed a more scientific realist approach by loosening empirical constraints, allowing the acceptance of the reality of unobservable entities and processes.
Death or Death of a Caricature?
The perception of the fate of logical positivism is reflected in the quote by John Passmore: “Logical positivism, then, is dead, or as dead as a philosophical movement ever becomes.” (Passmore, 1967, p. 57). In truth, as a movement, it died out, yet its ideas continued. A fact that is often neglected.
Perhaps unjustly, logical positivism mainly lived on as a caricature of philosophy, one of scientism through its attribution of meaninglessness to metaphysics in relation to science. Yet, they did not dismiss philosophy or take metaphysics, ethics, and aesthetics to be useless—just lacking in truth value.
Another caricature is that the positivists refused to acknowledge anything unobservable, yet there is a difference between acknowledging its reality and its scientific reality. While they were skeptical of them, they mainly did not want to assign a truth value to them. They instead took unobservable entities and processes to be tools for prediction, a view not far off from modern scientific anti-realism.
A. J. Ayer’s Influence
Much of the caricaturization of logical positivism comes from interpreting the movement as shaped by A. J. Ayers’s second-hand writing about the Vienna Circle. Ayers was the first cohesive translation to the anglophone audience and was much more accessible than someone like Carnap. This can be said in the anglospheres’ focus on the verifiability criterion, which was not meant to be a proposal of the world, meaning it would not undermine itself and the principle, something that someone like Carnap did not adhere to as opposed to Ayer’s view of it shaping the movement.
Ultimately, it was less the positivistic notion that went down but the general simplistic view of science as an entirely rationalistic, empirical enterprise. Together with the logical positivist hopes of a unifying language and the usage of the philosophy of language for truth assignment. With positivists’ lofty and laudable goals, deriding them for this may be unfair. Characteristics of the movement are maintained in modern philosophy of science as seen through naturalism and positivism.
Bibliography
Friedman, M. (1999). Reconsidering logical positivism (1. publ). Cambridge Univ. Press.
Passmore, J. A. (1967). Logical Positivism. In P. Edwards (Ed.), The Encyclopedia of Philosophy (pp. 52–57). Macmillan.
Quine, W. V. O. (1951). Two Dogmas of Empiricism. Philosophical Review, 60(1), 20–43. https://doi.org/10.2307/2266637
Verhaegh, S. (2024). Logical Positivism: The History of a “Caricature.” Isis, 115(1), 46–64. https://doi.org/10.1086/728796
