While logical realists and Popper argue that scientific knowledge is accumulated through the testing of hypotheses, Quine argues that entire bodies of knowledge, rather than individual hypotheses, should be tested through experience, which explains the change and development of knowledge.
Logical realists and Popper distinguish between knowledge that is independent of experience, such as mathematical or logical knowledge, and knowledge that depends on experience, such as scientific knowledge. They argue that scientific knowledge is accumulated by the scientific method. Hypotheses are candidates for scientific knowledge, and they propose a scientific method for testing hypotheses by determining whether the predictions logically derived from the hypothesis are correct or incorrect through experience, such as observation or experimentation. Logical positivists argue that if the prediction is correct, Popper argues that the hypothesis that led to the prediction is added as new knowledge, one by one, unless the prediction is incorrect.
However, Quine does not believe that predictions can be logically derived from hypotheses alone. For example, the hypothesis that a newly discovered metal M expands when heated does not lead to the prediction that M will expand when heated. First, we need the existing knowledge that all metals we have observed expand when heated, and the condition that M is heated. In this way, a prediction can only be logically derived from a combination of hypotheses, existing knowledge, and conditions. Therefore, if a prediction turns out to be false, it is impossible to know exactly what caused the prediction to fail. From this, Quine proposes holism, in which all knowledge, including not only individual hypotheses but also all existing knowledge and conditions, is subject to empirical testing.
Logical realists and Popper distinguish between analytic propositions that are true independent of experience, such as mathematical or logical knowledge, and synthetic propositions that are true through experience, such as scientific knowledge. However, Quine offers an argument that negates this distinction in order to justify holism. According to the logical positivist-Popperian distinction, both homophonic propositions, such as “a bachelor is a bachelor,” and those that are reducible to homophonic propositions, such as “a bachelor is an unmarried adult male,” are analytic propositions. The latter is an analytic proposition because it is reducible to the former. This reducibility is possible because “bachelor” and “unmarried adult male” are agreeable expressions, and if you ask why they are agreeable expressions, you will be told that substituting them for each other does not change the truth or falsity of the proposition. However, this is not enough to guarantee that the two expressions have the same meaning, so we again rely on the notion of inevitability, which states that agreeable expressions must always be interchangeable. This leads to a circularity in which the notion of necessity relies on the notion of analytic propositions, which in turn relies on the notion of analytic propositions, which in turn relies on the notion of homologous repetition. Thus, Quine concludes that the claim that analytic propositions are distinct from synthetic propositions is unfounded.
Instead of a strict division of knowledge into analytic and synthetic propositions, Quine envisions a central body of knowledge that does not directly conflict with experience, and a peripheral body of knowledge that can directly conflict with experience. Unlike peripheral knowledge, which can easily change between true and false in direct conflict with experience, the central knowledge that underlies peripheral knowledge is relatively robust. However, Quine does not distinguish between central and peripheral knowledge because the boundaries between the two are not clearly defined. Mathematical or logical knowledge is in the center of central knowledge, furthest away from experience, but not independent of it. However, when peripheral knowledge conflicts with experience and turns out to be false, the question arises as to which part of the total knowledge should be revised. Correcting the peripheral knowledge will not change the total knowledge much, but correcting the central knowledge will change the total knowledge significantly because there are many other knowledge related to it. Therefore, in most cases, we would choose to modify peripheral knowledge, but sometimes we need to modify central knowledge for practical reasons. Thus, Quine argues that both central and peripheral knowledge can in principle be subject to revision, and that knowledge change is no longer a simple accumulation of individual knowledge.
Even if the objections raised against a particular hypothesis seem conclusive, holism can always find a way around them and accept the hypothesis if it is recognized as pragmatically necessary. However, holism has the difficulty of answering the criticism that, like laws of logic such as “A cannot be both A and not A,” knowledge that no one doubts should be classified as analytic propositions. However, despite these criticisms, Quine also discusses how a holistic approach can be utilized in the accumulation of scientific knowledge. For example, complex scientific theories are not completely discarded by simple experimental disproof, but rather evolve through a process of revision and refinement that takes into account a variety of variables. This exemplifies the holistic view that scientific research is more than just the verification or disproval of a hypothesis, but involves a process of adjustment and adaptation within an entire body of knowledge.
Quine’s argument has been highly influential in modern philosophy and epistemology of science. The recognition that change and development of scientific knowledge is not a simple accumulation, but involves complex processes of interaction and coordination, deepens our understanding of the nature of science and provides a more realistic research methodology. Scientists are now able to move beyond mere disproversialism and pursue new discoveries and innovations through a more integrated and flexible approach.
Thus, Quine’s holism emphasizes the dynamism and complexity of knowledge, which provides deeper insights into the nature of knowledge and scientific methodology. This has important implications for how we understand, construct, and apply knowledge. Scientific inquiry is now moving beyond mere hypothesis testing and toward an integrated understanding and continuous development of the entire body of knowledge.
