Current programs sponsored by science foundations such as the American Association for the Advancement of Science emphasize the importance of "science literacy" in both K-12 and higher education. College curricula have pursued these goals through science-literacy requirements or specialized science courses for nonscience majors. Much has been written about what science literacy is, with varying emphasis between the process of science and the knowledge generated by that process.
That's all well and good, but relatively little attention has been spent on why we think science literacy is so important. Statements on the subject often begin with perfunctory justification; the value of science literacy is treated as self-obvious. And "literacy" sounds a bit defensive, laboring to justify the importance of science by defining it in terms of an essential fluency. We don't talk about "philosophical literacy." It seems as if we are straining to justify ourselves in response to religious fundamentalists and postmodernists who seek to constrain or diminish science education.
If science education is important for all Americans, then we need persuasive justifications for emphasizing science for all students in college curricula. I think the most common rationales are not terribly successful. One is that Americans' scores on science-literacy surveys are poor in comparison with other developed nations. That is certainly cause for alarm, but it is not unique to science. Surveys of basic knowledge about history, for example, show similar results. I'm sure that Americans, over all, don't have a good working knowledge of music, either. In general, we are more ignorant than we should be, but that doesn't suggest why we should be fluent in the language and theory of science in particular.
Another common justification for promoting science literacy holds that basic scientific knowledge is an imperative to be able to function in an increasingly technological society. Citizens need scientific knowledge to make better decisions in their lives. But that justification is unsatisfying, because it conflates science and technology and leads to the conclusion that knowledge of science is simply a practical matter. Surveys have shown that Americans have a poor understanding of why there are seasons. Should we teach every American about orbital mechanics? That knowledge wouldn't change the nature of the seasons or when people decide to put on a heavier coat. Likewise, the relationship between matter and energy isn't immediately useful unless you are building a nuclear reactor. The practical-knowledge argument is a trap.
Many have argued that investment in science education makes economic sense. That is a major theme in the work of Thomas Friedman, of The New York Times. The central argument is persuasive: Demand for technically skilled workers is increasing, and American education is not supporting that demand. But, again, this tends to conflate science and technology, and emphasizes the practical over the theoretical. It also marries science to the economic machine in a way that may not be entirely desirable. When certain areas of inquiry no longer lead to obvious profit, they could, under this line of reasoning, be abandoned. And some forms of technological economic growth may actually be in tension with some of the major themes in environmental science.
Furthermore, vocational justifications are problematic in liberal-arts curricula, in which broad intellectual skills and knowledge are favored over narrow training for specific careers.
Next, there is the citizen-scientist justification. In a democracy, all citizens are involved—at least indirectly—in making policy. If policies are to be informed by scientific knowledge, then voting citizens must have a working understanding of scientific principles: An educated populace makes for better government. This argument seems to be a bit more successful in that it provides a rationale for why understanding major theories and the process of science is broadly informative. Politically motivated arguments against evolution and climate change would be less successful if the voting public had a good grasp of the tremendous explanatory power of the natural sciences.
While this provides a more convincing rationale for why all Americans should be scientifically literate, it falls short of explaining why science in particular should be highlighted. Solutions to political problems will not come solely from scientific theories; a good grasp of Keynesian economics is critical for current political conversations, too.
I think there may be a better reason that science literacy should be a major component of higher-education curricula. There is something transcendent about studying science. The humanities and social sciences, for the most part, concern themselves with the creations of human beings, our behavior, or the structure of our societies. In contrast, the sciences force us to confront the smallness and irrelevance of human beings; they serve as an antidote to self-obsession. Physics teaches us that time and matter are not absolutes; biology, that astonishing complexity can arise from a long, natural, stepwise process. The scope and existential implications of these ideas are immense.
Just as theology once provided the organizing themes for all knowledge, science frames much of the 21st-century consciousness. The "big ideas" of science provide the foundation for understanding our universe. Practical understandings, such as those needed for better health and good citizenship, arise from these key ideas.
I do not mean to suggest that science should be studied at the expense of other disciplines, nor that science education should necessarily lead students to atheism. Indeed, science is best understood when it is placed in the context of human creations and history—studying science is, after all, a human activity.
An integrated conversation among disciplines is an important aspect of the kind of flexible, higher-order thinking to which we aspire. Yes, all college students—all students generally—should become scientifically literate. And if they become better, more employable citizens in a more competitively viable America, all the better. But first and foremost, they should become scientifically literate because, to borrow Darwin's phrase, "there is grandeur in this view of life."