Quinn replies: The range of responses in a way illustrates my point: Words mean different things to different people. If we wish to be understood we must explore the meaning our listener is taking from what we say, and not just repeat our words. I doubt that elevating certain theories by calling them laws will help, though my suggestion that we say we know these things has a similar didactic bent. In the end we can only attempt to communicate better and, as Lincoln Wolfenstein points out, to do a better job of education about both the power and the limitations of scientific knowledge.
“Know” and “knowledge” are just examples of words that have different meanings in everyday usage, in the discourse of scientists, and in that of philosophers. I think most people are quite happy to say they know that the Sun will rise again tomorrow, though from a philosophical point of view that is merely a well-grounded hypothesis. When I recommend that we say we know some things based on well-established scientific theories, I am suggesting that for the sake of better communication, we accept our audience’s idea of what it means to know something. I disagree with Fritz Rohrlich that we must teach the “correct meanings” of words. One usage is no more correct than another, language being a fluid thing. Instead, we must be willing to carry on the discourse long enough and with enough respect for our audience, be they students, interested members of the public, or other scientists, that we come to a shared understanding.
All our scientific knowledge rests on a set of conjectures or postulates that we cannot prove a priori; in this I agree with Kurt Huddleston. I argue, and I think he would agree, that a posteriori, these provide a very useful way to interpret the world around us. This approach has led to many medical and technical developments that we now depend on, as well as deep and interesting insights of a less practical nature. What one concludes about the world certainly rests on the assumptions one takes as primary. There is a direct contradiction between the conclusions from certain versions of religious belief, particularly those based on the belief that the Bible presents literal truth, and scientific conclusions about evolution, whether of the universe or of the species that populate Earth. When a student struggles with that contradiction, we should acknowledge and respect the struggle. We cannot avoid the contradiction; instead we should admit it and continue down the path of science, presenting students not only with its conclusions but with its primary assumptions, and with some understanding of the multiple strands of evidence that support the scientific conclusions given those assumptions.
Thus I argue that we should teach science as science, and religion as religion. When we teach science, we need to do the best job we can of teaching both fundamental assumptions and practices and the conclusions to which they have led us. The key idea that experiment and observation are the arbiters of scientific conclusions differentiates the scientific worldview from others. That idea certainly has a power of its own. In the modern world, every student should have the chance to learn about it. Informed decisions on issues that involve scientifically derived information can only be made by consumers and citizens equipped to judge the value—and the uncertainties—of that information. Our job as science educators and communicators is to make the scientifically equipped portion of the public as large as possible. It is no mean task, and we do not achieve it better by disrespecting either the intelligence or the beliefs of those with whom we wish to communicate.
