There are three terms that are particularly relevant in discussions about science, especially when it comes to evolution: law, theory, and hypothesis. Throughout North America and elsewhere in the modern West, far too many people seem to think that a scientific explanation "starts as a hypothesis, but as more evidence is gathered it may become a theory and eventually a law," as pointed out by science educator Gerald Rau. [1] But this is a misconception, as also explained by the University of California Museum of Paleontology which goes on to add that "hypotheses, theories, and laws are rather like apples, oranges, and kumquats: one cannot grow into another, no matter how much fertilizer and water are offered." [2] Stephen J. Gould observed that in the American vernacular the term "theory" often seems to imply something less than a fact, as if it is "part of a hierarchy of confidence running downhill from fact to theory to hypothesis to guess" and fueling the rhetorical device of evolution being just a theory. [3] As a matter of fact, this misconception enjoys such enormous popularity that in a list of the top 15 myths about science put together by William F. McComas the number one myth is that "hypotheses become theories that in turn become laws." [4]
This myth is evidently being disseminated by Answers in Genesis, for example, as we see when Danny Faulkner expresses that same view in a multi-volume set they published. "Once we test a hypothesis many times, we gain enough confidence that it is correct, and we eventually begin to call our hypothesis a theory," he said. "So a theory is a grown-up, well-established hypothesis. At one time, scientists conferred the title of law to well-established theories." [5] But that is a mistaken notion. It may be what Answers in Genesis means by those terms but in scientific language a bit more precision is required. A theory is not a grown-up hypothesis and a law is not a matured theory. Hypothesis, theory, and law are actually three very different things, as I shall attempt to explain.
In science, a law is a generalization about empirical data that seeks to describe the regular and consistent patterns and relationships that are found. But these are descriptions, which are not explanations. That is the role of a theory, a concise unifying conceptual structure that ties together and explains observed and predicted empirical phenomena (causes, forces, etc.) and their relationships. Theories also encompass and integrate many different hypotheses, which are limited explanations of more narrow sets of phenomena. [6] Here is an example that should help to illustrate the difference between each term and their relationships to one another: A hypothesis about graviton particles might serve a general theory of gravitation proposed to explain the law of gravity.
With respect to any origins debate, all sides need to acknowledge and deal with the conspicuous and increasing wealth of empirical data showing that, one way or another, life evolves, wherein the history of life's biodiversity continues to leave behind an empirical record that consistently displays a pattern corresponding to the predictions of evolution, particularly common ancestry. This massive and growing volume of data from diverse scientific fields practically demands an explanation—which is what competing theories are supposed to do. Regarding life on our planet, scientific theories represent our best efforts at explaining the history of and relationships between species and they encompass any number of independently testable hypotheses that compete or coordinate, some being retained and refined while others are discarded and new ones proposed. [7]
Some examples of scientific theories are those regarding electromagnetism, infectious diseases, planetary orbits, climate change, gravity, plate tectonics and, yes, evolution. There certainly can be—and often are—rival theories attempting to explain the same facts, each with their own or shared hypotheses. This is particularly evident with respect to climate change. But the question is always a matter of which scientific theory best explains all the relevant data while also predicting new data that should be discovered if that theory were true (which is exactly how the fossil remains of Tiktaalik were discovered). [8] This is known as abductive reasoning or inference to the best explanation. It is what leads to invigorating, fruitful scientific investigations and research programs, frequently leading us to discover things previously unknown—and even some things beyond our imagination (e.g., dark matter).
-- John M. Bauer
@JohnMBauer1
Approx. 725 words
Footnotes:
[1] Gerald Rau, Mapping the Origins Debate: Six Models of the Beginning of Everything (Downers Grove, IL: IVP Academic, 2012), 33.
[2] University of California Museum of Paleontology, "Misconceptions about Science," Understanding Science: How Science Really Works (accessed June 14, 2019).
[3] Stephen Jay Gould, "Evolution as Fact and Theory," Discover (May 1981): 34–37.
[4] William F. McComas, "The Principal Elements of the Nature of Science: Dispelling the Myths," in William F. McComas, ed., The Nature of Science in Science Education: Rationales and Strategies, vol. 5 (Boston: Science and Technology Education Library, Kluwer Academic, 1998), 54. As cited in Rau, Mapping, 33n5.
[5] Danny Faulkner, "Do Creationists Believe in 'Weird' Physics Like Relativity, Quantum Mechanics, and String Theory?" in Ken Ham, ed., New Answers Book 2 (Green Forest, AR: Master Books, 2008), 326. Given the history of his education, including an MA and PhD in astronomy (Indiana University), and the fact that he is a full professor at the University of South Carolina–Lancaster where he teaches physics and astronomy, it would seem that Dr. Faulkner ought to know better. But such is the prevalence of this myth, I suppose.
[6] Ernan McMullin, "Hypothesis," in Wilbur Applebaum, ed., Encyclopedia of the Scientific Revolution From Copernicus to Newton (New York: Garland, 2000), 315-318; "Theory," ibid., 641-643; Helen Hattab, "Laws of Nature," ibid., 354-357; Carl G. Hempel, Philosophy of Natural Science (Englewood Cliffs, NJ: Prentice-Hall, 1966); New Encyclopedia Britannica, 15th ed., s.v. "Theory." APA Dictionary of Psychology, s.v. "Hypothesis," "Theory," and "Law."
[7] Sometimes empirical data can so persistently confute an idea that it has to be discarded. For example, Darwinian phyletic gradualism had to give way to a cladogenetic picture of punctuated equilibrium on account of population genetics, although both models explain evolutionary history in terms of common descent. There is also healthy scientific debate when it comes to whether or not the evolution of genetic traits must perforce be framed in terms of adaptive responses to selection pressures, an example of this being the observed cases of mutations that increase genetic complexity which are not driven by natural selection because they are neutral and thus "hidden." This has been called "the zero-force evolutionary law" by Daniel W. McShea and Robert N. Brandon, Biology’s First Law: The Tendency for Diversity and Complexity to Increase in Evolutionary Systems (Chicago: University of Chicago Press, 2010), 84–89. As cited by Carl Zimmer, "The Surprising Origins of Life's Complexity," Scientific American (August 2013), 84–89. On the adaptationism debate see for example Karen Neander, "Evolutionary Theory: The Adaptationism Debate," in Donald M. Borchert, ed., Encyclopedia of Philosophy, 2nd ed. (Farmington Hills, MI: Macmillan Reference USA, 2006), 489–490.
[8] For the full story, see Neil Shubin, Your Inner Fish: A Journey into the 3.5-Billion-Year History of the Human Body (New York: Pantheon, 2008). See also Denis R. Alexander, Creation or Evolution: Do We Have to Choose?, 2nd ed. (2008; Oxford, UK: Monarch, 2014), 150–153; Jerry A. Coyne, Why Evolution Is True (New York: Viking Penguin, 2009), 37–38.
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