Scientific realism
Scientific Realism
Scientific realism is a philosophical viewpoint that posits that the entities, processes, and structures described by scientific theories exist independently of our thoughts or perceptions. It asserts that the aim of science is to describe and explain the nature of the world as it truly is, and that successful scientific theories are at least approximately true representations of the world.
Historical Background
The roots of scientific realism can be traced back to the early modern period, particularly with the works of Newton and Galileo. These scientists believed that their theories and models provided true descriptions of the natural world. The debate over scientific realism gained prominence in the 20th century with the rise of logical positivism and the subsequent challenges posed by philosophers such as Popper, Kuhn, and Feyerabend.
Core Tenets
Scientific realism is underpinned by several core tenets:
Metaphysical Realism
This tenet asserts that the world exists independently of human minds and that scientific theories aim to describe this objective reality. It contrasts with idealism, which holds that reality is mentally constructed.
Epistemic Realism
Epistemic realism posits that scientific theories provide knowledge about the world that is at least approximately true. This implies that the success of scientific theories is not merely a matter of empirical adequacy but also of their truthfulness.
Semantic Realism
Semantic realism maintains that scientific language and theories have a literal interpretation, meaning that terms like "electron" or "black hole" refer to real entities in the world.
Arguments for Scientific Realism
Several arguments have been advanced in favor of scientific realism:
The No-Miracles Argument
One of the most compelling arguments for scientific realism is the no-miracles argument, which suggests that the success of science would be miraculous if scientific theories were not at least approximately true. This argument posits that the best explanation for the empirical success of scientific theories is that they accurately describe the world.
The Success of Science
The historical success of science in producing reliable and predictive theories is often cited as evidence for scientific realism. For example, the predictive power of quantum mechanics and the explanatory success of evolutionary biology are seen as strong indicators that these theories are true or approximately true.
Convergence of Scientific Theories
The convergence of independent scientific theories on the same phenomena is also used to support scientific realism. When different theories developed independently arrive at similar conclusions, it suggests that they are converging on a true description of the world.
Challenges to Scientific Realism
Despite its strengths, scientific realism faces several significant challenges:
The Pessimistic Meta-Induction
The pessimistic meta-induction argument suggests that because many past scientific theories have been proven false, current theories are likely to be false as well. This argument challenges the notion that the success of a theory implies its truth.
Underdetermination of Theory by Evidence
The underdetermination thesis posits that for any given set of empirical data, there can be multiple scientifically valid theories. This implies that empirical evidence alone cannot determine which theory is true, challenging the realist's claim that successful theories are true.
Theory-Ladenness of Observation
The theory-ladenness of observation suggests that what we observe is influenced by the theoretical framework we use, implying that our observations are not purely objective. This challenges the realist's claim that scientific theories provide a true description of the world.
Varieties of Scientific Realism
Scientific realism is not a monolithic position; there are several varieties, each with its nuances:
Entity Realism
Entity realism focuses on the existence of specific entities posited by scientific theories, such as electrons or DNA. Entity realists argue that the success of experimental practices involving these entities provides strong evidence for their existence.
Structural Realism
Structural realism posits that what science accurately describes is not the individual entities themselves but the structure of the relationships between them. This view is often associated with the work of Poincaré and has been further developed by contemporary philosophers like Worrall.
Epistemic Structural Realism
Epistemic structural realism holds that we can only know the structure of the world, not the nature of the unobservable entities themselves. This view attempts to reconcile the success of science with the historical record of theory change.
Ontic Structural Realism
Ontic structural realism goes further, claiming that structure is all there is. According to this view, the world is fundamentally composed of structures rather than individual objects.
Scientific Realism and Scientific Practice
Scientific realism has significant implications for scientific practice:
Theory Choice
Scientific realism influences how scientists choose between competing theories. Realists argue that scientists should prefer theories that provide the best explanation of the phenomena, rather than merely those that are empirically adequate.
Scientific Progress
Realists view scientific progress as a cumulative process where successive theories build on and improve upon their predecessors. This contrasts with Kuhn's theory of scientific revolutions, which sees scientific progress as a series of paradigm shifts.
The Role of Experiments
Experiments play a crucial role in scientific realism by providing evidence for the existence of unobservable entities and validating theoretical predictions. The realist interpretation of experiments emphasizes their role in revealing the true nature of the world.
Criticisms and Alternatives
Scientific realism is not without its critics, and several alternative viewpoints have been proposed:
Instrumentalism
Instrumentalism holds that scientific theories are merely tools for predicting and controlling phenomena, without any commitment to their truth. According to this view, the value of a theory lies in its usefulness rather than its truthfulness.
Constructive Empiricism
Constructive empiricism, proposed by van Fraassen, argues that the aim of science is to produce empirically adequate theories rather than true ones. Constructive empiricists maintain that we should only believe in the observable aspects of scientific theories.
Pragmatism
Pragmatism emphasizes the practical consequences of scientific theories rather than their truth. Pragmatists argue that the value of a theory lies in its ability to solve problems and guide action, rather than its correspondence to an objective reality.
Relativism
Relativism challenges the notion of objective truth, arguing that scientific knowledge is relative to specific cultural or historical contexts. Relativists maintain that what counts as true or rational is determined by social and cultural factors.
Conclusion
Scientific realism remains a central and contentious issue in the philosophy of science. While it provides a compelling account of the success of scientific theories and their ability to describe the world, it faces significant challenges from alternative viewpoints. The ongoing debate between realists and anti-realists continues to shape our understanding of the nature of scientific knowledge and the aims of scientific inquiry.