The Meaning of Science: An Introduction to the Philosophy of Science

Book Preface

The achievements of the sciences are extraordinary. They have produced explanations for everything from the origins of human culture to the mechanisms of insect navigation, from the formation of black holes to the workings of black markets. They have illuminated our moral judgments and our aesthetic sensibilities. Their gaze has fallen on the universe’s most fundamental constituents and its very first moments. They have witnessed our intimate private activities and our collective public behaviors. Their methods are so compelling that they can command consensus even when dealing with events that are invisible or intangible, in the distant past or the distant future. Because of this, the sciences have alerted us to some of the most pressing problems facing humanity, and the sciences will need to play central roles if these problems are to be solved.

This book—an introduction to the philosophy of science—steps back from the particular achievements of the sciences to ask a series of questions about the broad significance of scientific work. It is a book for anyone with an interest in what we mean by “science,” and in what science means for us. It does not assume any scientific knowledge, nor does it assume any familiarity with philosophy.

The philosophy of science, like all branches of philosophy, has existed since the time of the ancient Greeks. And like all branches of philosophy, it has a mixed reputation. The charismatic American physicist Richard Feynman—a recipient of the Nobel Prize for physics in 1965—had little patience for the subject, allegedly remarking that “philosophy of science is about as useful to scientists as ornithology is to birds.”¹

Feynman’s words—assuming he really said them—were ill chosen. Ornithology is useless to birds because birds cannot understand it. If a bird could only learn what ornithologists know about how to recognize a cuckoo chick in its brood, then that bird could save itself a lot of misguided effort. Of course, Feynman didn’t mean to suggest that philosophy was too complicated for scientists to comprehend; he just didn’t see any evidence that philosophy could contribute to scientific work.

There are many good ways to respond to this challenge. One comes from a physicist whose stature is even greater than Feynman’s. In 1944, Robert Thornton, freshly qualified with a PhD in the philosophy of science, began teaching modern physics to students at the University of Puerto Rico. He wrote to Albert Einstein for advice. Should he introduce philosophy into his physics course? Einstein wrote back with an unequivocal “yes.” “So many people today,” he complained, “and even professional scientists—seem to me like somebody who has seen thousands of trees but has never seen a forest.” Einstein went on to describe the antidote to this myopia:

A knowledge of the historic and philosophical background gives that kind of independence from prejudices of his generation from which most scientists are suffering. This independence created by philosophical insight is—in my opinion—the mark of distinction between a mere artisan or specialist and a real seeker after truth.²

For Einstein, the value of the philosophy of science, in combination with the history of science, lay in its ability to liberate the investigator’s imagination.³

We will see in this book that the sciences have been admirably ambitious in bringing their methods to some of the most profound topics the world presents us with. Psychologists, evolutionists, and neuroscientists have grappled, for example, with the nature of ethics and the reality of free choice. Once they venture down these investigative pathways, it is impossible for them to avoid engagement with philosophy. Scientists cannot make plausible pronouncements about the repercussions of evolutionary theorizing for human morality, they cannot assess the fate of free will in the face of work in neuroscience, unless they have well-formulated views about what morality, or freedom of the will, involve. In other words, whether they like it or not, scientists end up running into exactly the same conceptual issues that have puzzled philosophers for centuries.

This does not mean that philosophers have nothing to learn when scientists begin to colonize territory that has traditionally belonged to the humanities. On the contrary, recent philosophical work on topics like morality and free will has been greatly enriched by its interactions with the best scientific research on evolution, the mind, and social behavior. In areas like these, philosophy and the sciences have repeatedly come together in constructive ways. They have learned from each other.

We should not suppose that the value of the philosophy of science is fully measured by the degree to which it helps scientists. It also has general cultural significance. The sciences look everywhere, but do they see everything? Will they eventually teach us all that is worth knowing? Or are there alternative forms of understanding that must be arrived at in other ways, perhaps by engaging with works of literature, perhaps by abstract reflection? Philosophical questions like these concern the reach of science, and they help us to understand how the sciences and the arts make different kinds of contributions to human knowledge.

The philosophy of science also has direct political relevance. We cannot ascertain how governments should respond to threats from climate change without first determining how we should reason when our evidence is uncertain and when the stakes are momentous. We cannot decide whether homeopathic treatments should be funded by public health budgets without asking about the markers of genuine science and the markers of pseudoscientific quackery. We cannot assess how democratic states should make use of technical scientific advice without inquiring about whether apparently neutral pieces of scientific information already come laden with moral and political values.

It turns out, in other words, that the issues addressed by the philosophy of science—the issues we will explore in this book—matter in the most practical ways, for the most important questions of all.