Various criteria for categorizing science have been proposed, including logical positivism’s verifiability, logical empiricism’s confirmability, and Popper’s disprovability, but each has its limitations. This essay critiques the main criteria in philosophy of science for solving the compartmentalization problem and explores the need for a more comprehensive and valid distinction between science and non-science.
Parapsychology is the study of paranormal psychological phenomena related to psychic powers, the spiritual world, spiritual beings, and spiritual abilities. Long rejected as a science, parapsychology was officially recognized in 1969 when the American Association for the Advancement of Science approved the Parapsychological Society as a cooperating organization. However, many scientists didn’t like this decision, considering parapsychology a pseudoscience. So, is parapsychology a science? Before we can answer that question, we need to think about what science is.
The problem of distinguishing science from non-science is known in philosophy of science as the compartmentalization problem. It is a major topic in the philosophy of science, first explored by E. Mach, J. H. Poincare, and P. Duhem, and later by logical positivists such as L. Wittgenstein, M. Schlick, R. Carnap, and H. Reichenbach. It was also a major concern of K. Popper’s methodological reflections on science. Each philosopher of science proposed a criterion for distinguishing science from non-science: the early logical positivists argued for verifiability, while later logical positivists and logical empiricists described it as confirmability. Popper pointed out the problems with these criteria and proposed the criterion of disprovability.
However, Popper’s criterion has also been criticized by scholars of the new philosophy of science, including T. S. Kuhn, N. R. Hanson, and P. K. Feyerabend. In this essay, I will criticize the criteria of logical positivism, logical empiricism, and disproversialism, respectively, from the perspective of the new philosophy of science, criticize the compartmentalization criteria proposed in the philosophy of science, and seek improvements for solving the compartmentalization problem.
First, logical positivism can be seen as a combination of Comte and Mill’s positivism and modern logic in the 20th century. Logical positivists accept Mach’s position that modern science is based on direct experience and that scientific theories are derived inductively from observations. They hold the phenomenalist position that scientific inquiry must begin with objective observations and be expressed in a neutral observational language that is independent of all theories. Logical positivists view scientific theories as “deductive systems of scientific propositions,” and only scientific propositions have meaning. For them, the distinction between science and non-science is a matter of distinguishing between meaningful and meaningless propositions, and the criterion of meaningfulness is considered to be the criterion for distinguishing between science and non-science.
They argued for the principle of verification as a criterion of meaningfulness, which in turn made verifiability a criterion of science and non-science. For a proposition to be considered meaningful, it must be verifiable. By this criterion, logical positivists attempted to distinguish scientific propositions from meaningless propositions, but crucially, the only verifiable propositions were those that could be directly verified by current perception, such as historical or observational propositions. As a result, not only metaphysical propositions but also a wide range of propositions in value philosophy, ethics, aesthetics, and so on were considered meaningless and unscientific. Eventually, logical positivists abandoned the criterion of conclusive verifiability.
The logical empiricists who came after logical positivism proposed a weakened version of this criterion, called confirmability. Confirmability means that a proposition is meaningful if it is at least partially verifiable. Logical empiricists attempted to explain the meaning formation of scientific concepts by analyzing the corroboration relationship between scientific laws and the observational statements that confirm or disprove them.
According to the confirmability criterion, a proposition has meaning if it can be plausibly confirmed empirically. For example, the law of universal gravitation, the law of thermodynamics, etc. can be confirmed as universal propositions under certain conditions. By this standard, propositions about the past and future are also considered meaningful through inductive reasoning and observing the behavior of others. Metaphysical propositions, however, remain meaningless. This verifiability criterion attempts to solve the problem faced by the verifiability criterion of logical positivism, but it runs into a logical problem known as the “reverse logic of verification”. For example, if we have a hypothesis that “all crows are black,” it is possible for a white swan that is not a crow to confirm this hypothesis. This calls into question the validity of the confirmability criterion.
Popper criticized the significance criteria of logical positivism and logical empiricism as inadequate for the distinction between science and non-science, and proposed a new criterion: disprovability. He believed that verification and corroboration do not have logical justification based on an inductive view of science, and proposed disprovability as a criterion for distinguishing pure science from non-science. Popper argued that in order for a scientific proposition to be recognized as scientific, it must be disprovable. His criterion distinguishes non-science from science by its metaphysical or pseudoscientific elements, not by its irrelevance, and the disprovability criterion is based on the rules of the scientific method (problem, new theory, deduction of propositions, attempts at refutation, competition between theories).
While Popper’s criterion of disprovability seems to be an alternative to the problems of logical positivism and logical empiricism, the bias toward understanding the basis of scientific observation and science in purely logical terms remains. This has been criticized by Kuhn, FireAvent, and others.
They have criticized logical positivism, logical empiricism, and antipositivism, and found them to be imperfect as a distinction between science and non-science. They have three common problems. First, they presuppose pure observation and neutrality independent of scientific theories; second, they attempt to make science rely solely on inductive or deductive rules; and third, they assume that scientific discovery and justification can be separated. These issues have led to the compartmentalization problem remaining unresolved and sparking new debates. However, the criteria proposed by compartmentalists have not simply remained a subject of debate, but have led to attempts to address the issue of compartmentalization from a historical perspective, rather than a methodological one.
