Logical positivism is a school of philosophy, originating in Vienna during the 1920s and 1930s, that claimed that “real” knowledge is based on logical consistency and empirical verifiability. If either condition is contravened, the claim to knowledge is spurious or “nonsense.” But if both conditions are met, truth is guaranteed.
The search for clear criteria to separate true meaningful statements from false meaningless ones has preoccupied philosophers ever since there have been philosophers. Those who gathered around Moritz Schlick in Vienna during the interwar period (the “Vienna Circle”) and who included some of the 20th century’s most preeminent philosophers—Oscar Neurath, Rudolf Carnap, Herbert Feigl, and Friedrich Waismann as well as (on the fringes) Karl Popper and Ludwig Wittgenstein—believed they had the answer.
Building on French philosopher and sociologist Auguste Comte’s earlier 19th-century philosophy of science, positivism, logical positivists argued that there are just two types of true meaningful statements, each of which can be defined and delineated precisely.
• Analytical statements are true and meaningful by virtue of their definition and have a logical connection with one another. The paragon example is mathematics. Based on self-defined primitive axioms and the purest form of logical derivation, mathematical statements are tautological. That is, they are true by definition and therefore unassailable. Analytical statements are the basis of the formal sciences, logic, and mathematics.
• Empirical or synthetic statements are empirically verifiable; that is, they can be proven true or false unambiguously by comparing them with real-world observations. The most important of such statements are enduring empirical regularities—laws—which in turn are a necessary component of scientific explanation. Sciences in which the principle of verification is applicable are the factual sciences. However, a lot is left out from these two categories. For example, aesthetic judgment, moral argument, political opinion, and various forms of metaphysical speculation all represent spurious knowledge from logical positivism’s perspective. Such discourses might spark interesting debates, but they do not meet the criteria of scientific knowledge, the only standard for an epistemology of objective explanation.
Not surprisingly, the period when geography most endeavored to follow the strictures of logical positivism was when it strove to achieve objective explanation— to be a science. That episode, which was known as the quantitative revolution and began during the mid-1950s, was associated with importation into the discipline of both scientific theory and sophisticated statistical techniques of description and empirical verification. The first shot in that revolution was an article titled “Exceptionalism in Geography” by Fred Schaefer, a German political émigré at the University of Iowa and a friend and Iowa colleague of Gustav Bergmann, former member of the Vienna Circle. This article was a plea for pure logical positivism. Arguing against an older regional geography concerned with mere description of unique places, Schaefer urged objective explanation based on discovering empirically verified morphological laws. A morphological law is an empirically verified repeated association between one geographic event and another. For Schaefer, morphological laws are the geographic equivalent of the laws of natural science; following logical positivism, they are necessary for objective explanation.
After Schaefer’s manifesto, much of the quantitative revolution was driven less by grand philosophical statements than by a desire for technical competence in specific theories and techniques. Ironically, the next important disciplinary statement about logical positivism, David Harvey’s tome Explanation in Geography also functioned as a memorial for it. Harvey’s book was the most comprehensive and rigorous philosophical justification of logical positivism ever put forward in the discipline. It paid as much attention to the kinds of analytical statements that logical positivist geographers could make in mathematics, logic, and (especially) geometry as it did to their synthetic statements, particularly their use of the verification principle embodied in particular statistical techniques. But almost as soon as he wrote the book, and by some accounts even before he finished it, Harvey had doubts about the logical positivist project that lay at the volume’s center. In many ways, it was the wrong book at the wrong place and wrong time. Even by the 1940s, people associated with the Vienna Circle, such as Wittgenstein and Popper, had become critics, arguing for contrary positions. And by the 1960s, the idea of law-driven, objective scientific explanation was unraveling quickly. Thomas Kuhn, in The Structure of Scientific Revolutions, undermined the notion of independent facts (synthetic statements) by arguing that they never are pure; they always are tainted by social and personal values. Popper claimed that scientific theories never are verified anyway; they are only falsified. And Imre Lakatos, in Criticism and the Growth of Knowledge, went one step further, arguing that the internal architecture of scientific theories prevents both verification and falsification. Scientific programs rise and fall, but not on the basis of the quality of their synthetic or analytic statements. Subsequently, science studies, a body of literature critically examining the practice and epistemology of science, has only deepened these objections to logical positivism’s binary agenda.
It is unclear which of these criticisms was most crucial in Harvey’s about-face. But within 2 years of the publication of Explanation, he publicly rejected the quantitative revolution, and the concomitant philosophy of logical positivism, instead propounding Marxism as an alternative. ertainly, a key problem with logical positivism for Harvey, but one of the rationales for its originators, was the exclusion of the
political. Logical positivism strove for unbesmirched certainty anchored in either pure facts or pure logic; anything impure, such as politics, was xcluded. For Harvey, however, impurity was fundamentally interesting. It was where life and its problems were lived. To omit impurity was to omit what made geography a relevant and compelling discipline.