Philosophy of Science

A Contemporary Introduction

Alex Rosenberg

• Publisher: Routledge
• Year: 2011
• ISBN:
  9781136662614
• Edition: 3
• Topic: Filosofia
• Subtopic: Storia e teoria della filosofia

Any serious student attempting to better understand the nature, methods and justification of science will value Alex Rosenberg's updated and substantially revised Third Edition of Philosophy of Science: A Contemporary Introduction. Weaving together lucid explanations and clear analyses, the volume is a much-used, thematically oriented introduction to the field.

New features of the Third Edition include more coverage of the history of the philosophy of science, more fully developed material on the metaphysics of causal and physical necessity, more background on the contrast between empiricism and rationalism in science, and new material on the structure of theoretical science (with expanded coverage of Newtonian and Darwinian theories and models) and the realism/antirealism controversy. Rosenberg also divides the Third Edition into fifteen chapters, aligning each chapter with a week in a standard semester-long course. Updated Discussion Questions, Glossary, Bibliography and Suggested Readings lists at the end of each chapter will make the Third Edition indispensable, either as a comprehensive stand-alone text or alongside the many wide-ranging collections of articles and book excerpts currently available.

Read our interview with Alex Rosenberg, What exactly is philosophy of science – and why does it matter? here: www.routledge.com/u/alexrosenberg

1	Philosophy and Science

• Overview

• What Is Philosophy?

• Philosophy and the Emergence of the Sciences

• Science and the Divisions of Philosophy

• What if There Are No Questions Left Over when Science Is Finished?

• A Short History of Philosophy as the Philosophy of Science

• Summary

• Study Questions

• Suggested Readings

Overview

Philosophy of science is a difficult subject to define in large part because philosophy is difficult to define. But for at least one controversial definition of philosophy, the relation between the sciences—physical, biological, social, and behavioral—and philosophy are so close that philosophy of science must be a central concern of both philosophers and scientists. On this definition, philosophy deals initially with the questions the sciences cannot yet or perhaps can never answer, and with the further questions of why the sciences cannot answer these questions.

The chapter argues for the adequacy of this definition in a number of different ways. It shows how the sciences emerged successively from philosophy, how the subdivisions of philosophy are related to the sciences and how the history of philosophy reflects an agenda of problems set by the sciences.

What Is Philosophy?

Philosophy is not an easy subject to define. Its etymology is obvious—the love of wisdom, but unhelpful to someone who wishes to understand what the discipline of philosophy is about. Nor is it enough to know what the most important sub-disciplines of philosophy are. Its major components are easy to list, and the subjects of some of them are even relatively easy to understand. The trouble is trying to figure out what they have to do with one another, why combined they constitute one discipline—philosophy, instead of being parts of other subjects, or their own independent areas of inquiry.

The major subdisciplines of philosophy include logic—the search for well-justified rules of reasoning; ethics (and political philosophy), which concerns itself with right and wrong, good and bad, justice and injustice, in the conduct of individuals and states; epistemology¹ or the theory of knowledge—the inquiry into the nature, extent and justification of human knowledge; and metaphysics, which seeks to determine the most fundamental kinds of things there are in reality and what the relations between them are. Despite its abstract definition, many of the questions of metaphysics are well known to almost all people. For example, “Is there a God?” or “Is the mind just the brain, or something altogether non-physcial?” or “Do I have free will?” are all metaphysical questions most people have asked themselves.

But knowing these four domains of inquiry may deepen the mystery of what philosophy is. They don’t seem to have much to do with each other. Each seems to have at least as much to do with another subject altogether. Why isn’t logic part of mathematics, or epistemology a compartment of psychology? Shouldn’t political philosophy go along with political science, and isn’t ethics a matter ultimately for priests, ministers, imams and others who deliver sermons? Whether we have free will or if the mind is the brain is surely a matter for neuroscience. Perhaps God’s existence is something to be decided upon not by an academic inquiry but by personal faith. Yet, none of these disciplines or approaches in fact explores any of these questions in the way that philosophers pursue them. The problem thus remains, what makes them all parts of a single discipline, philosophy?

What is worse, now we have another question, one that will certainly occur to the reader of this book. The one compartment of philosophy that was not even mentioned in the list of its chief sub-disciplines is the philosophy of science. Yet that is the subject of the very book in your hands. Where does it fit in and how important can it be if it is not one of the four main areas of philosophical inquiry?

The answer to the question of what philosophy is that I prefer makes the philosophy of science at least as central to the whole subject as logic, ethics, epistemology and metaphysics. It also resolves the other matter of what makes one discipline out of these diverse topics. Nevertheless the definition of philosophy to be offered below is tendentious. It is a partisan definition, reflecting a distinctive point of view. In deciding whether you want to accept it, ask yourself whether other definitions can synthesize the diverse questions philosophers address better than this one:

Philosophy deals with two sets of questions:

First, the questions that science—physical, biological, social, behavioral— cannot answer now and perhaps may never be able to answer.

Second, the questions about why the sciences cannot answer the first lot of questions.

Philosophy and the Emergence of the Sciences

There is a powerful argument for this definition of philosophy in terms of its historical relationship with science.

Technology and engineering began in many places independently, and advance more rapidly in some places than others. China is the source of many of the most important advances in technology—paper, printing, gunpowder, and probably the magnetic compass, to name only the most obvious. Science, however, seems to have begun in the Near East, and to have taken off among the Greeks.

But the history of science from the ancient Greeks to the present is the history of one compartment of philosophy after another breaking away from philosophy and emerging as a separate discipline. But each of these disciplines which have spun off from philosophy, have left to philosophy a set of distinctive problems: issues they cannot resolve, but must leave either permanently or at least temporarily for philosophy to deal with. Thus, by the third century BC, Euclid’s work had made geometry a “science of space” separate from but still taught by philosophers in Plato’s Academy.

Soon after, Archimedes was calculating the approximate value of the irrational number π and finding ways to calculate the sum of an infinite series. But almost from the outset of its history as a discipline distinct from philosophy, mathematics turned its back on a series of questions that one might have thought would interest mathematicians profoundly.

Mathematics deals with numbers, but it cannot answer the question what a number is. Note that this is not the question what “2” or “dos’ or “II” or “10(base 2)” is. Each of these is a numeral, an inscription, a bit of writing, and they all name the same thing: the number 2. When we ask what a number is, our question is not about the symbol (written or spoken), but apparently about the thing. Philosophers have been offering different answers to this question at least since Plato held that numbers were particular things—albeit, abstract things not located in space and time. By contrast with Plato, other philosophers have held that mathematical truths are not about abstract entities and relations between them, but are made true by facts about concrete things in the universe, and reflect the uses to which we put mathematical expressions. But 2,500 years after Plato lived, there is as yet no general agreement on the right answer to the question of what numbers are.

The work of Galileo, Kepler, and finally Newton’s revolution in the seventeenth century made physics a subject separate from metaphysics. To this day, the name of some departments in which physics is studied is “natural philosophy.” But physics too has left profound problems to philosophy for centuries. Here is an important instance.

Newton’s second law tells us that F = ma, force equals the product of mass and acceleration. Acceleration in turn is dv/dt, the first derivative of velocity with respect to time. But what is time? Here is a concept we all think we understand, and one that physics requires. Yet both ordinary people and physicists, for whom the concept is indispensable, would be hard pressed to tell us what exactly time is, or give a definition of it. Notice that to define time in terms of hours, minutes and seconds, is to mistake the units of time for what they measure. It would be like defining space in terms of meters or yards. Space is measured with equal accuracy in meters or yards. But suppose we ask which is the correct way of measuring space? The answer of course is that there is no uniquely correct set of units for measuring space; yards and meters do equally good jobs. By the same token, neither can be said to “define” or constitute space. The same goes for time. Seconds, centuries, millennia are just different amounts of the same “thing”: time. And it’s that thing, time, which comes in different amounts we want a definition of. We could say that time is duration, but then duration is just the passage of time. Our definition would presuppose the very notion we set out to define.

Explaining exactly what “time” means is a problem which science left to philosophy for a period of at least 300 years. With the advent of the special and general theory of relativity physicists began to take a share in trying to answer this question again. Albert Einstein’s own reflections on time, which led to the conclusion that time intervals, durations, differ between different reference frames—points from which the durations are measured, owes much to philosopher’s critique of Newton’s conception of absolute space and time as independent containers in which things can be absolutely located and dated. Even today, while several important physicists address the question of why time has a direction, none take on the question of what time itself is. The matter is either premature or beyond physics.

Until the end of the nineteenth century many chemists treated the question of whether there were atoms or not as one beyond the reach of their discipline. Their refusal to debate the question stemmed from their epistemology—their theory of knowledge. The winner of the debate about whether atoms exist, Ludwig Boltzmann, one of the greatest scientists of the era, went to his early death believing he had lost the epistemological argument that we can have knowledge about atoms.

In biology the shift of questions from philosophy’s side of the ledger to science’s side is particularly clear. It was only in 1859 that The Origin of Species finally set biology apart from philosophy (and theology). Many biologists and not a few philosophers have held that after Darwin, evolutionary biology took back from philosophy the problems of explaining human nature or identifying the purpose or meaning of life. These biologists and philosophers hold that Darwinism shows that man’s nature differs only by degrees from that of other animals. They argue that Darwin’s great achievement was to show that there is no such thing as purposes, goals, ends, meaning or intelligibility in the universe, that its appearance is just an “overlay” we confer on the adaptations we discern in nature. Adaptations are really just the result of the environment’s persistent filtration of blind variations creating the appearance of design. It is for this reason that evolutionary theory is so widely resisted. Some people reject the answers biology gives to questions about purpose, meaning and human nature. Instead they turn to philosophy, or to religion. Whether one agrees with Darwin’s theory of natural selection or not, it is an impressive example of how scientific research leaves some questions to philosophy for centuries, and then takes them on when it considers itself finally equipped to do so.

In the last century psychology broke free from philosophy as a separate discipline, and began to address questions of the nature of the mind, the self, the will and consciousness which philosophy had been taking seriously for two and a half millennia. And of course, in the last 50 years, philosophy’s enduring concern with logic has given rise to computer science as a separate discipline.

The lesson is clear. Every science is a child of philosophy. Each eventually moves out, but ends up leaving “baggage” at home.

Science and the Divisions of Philosophy

There are other questions science appears to be unable to address: the fundamental questions of value, good and bad, rights and duties, justice and injustice that ethics and political philosophy address. Scientists have views on these matters. In fact they disagree as much with one another about them as non-scientists do. But since scientists generally agree on the broadest matters of their sciences, it is hard to avoid the conclusion that science can’t decide these questions.

Questions about what ought to be the case, what we should do, about what is good and bad, right and wrong, just and unjust are called “normative.” By contrast questions in science are presumably descriptive, or as is sometimes said, positive, not normative. Many of these normative questions have close cousins in the sciences. Thus, psychology will interest itself in why individuals hold some actions to be right and others wrong, anthropology will consider the sources of differences among cultures about what is good and bad, political scientists may study the consequences of various policies established in the name of justice, economics will consider how to maximize welfare, subject to the normative assumption that welfare is what we ought to maximize. But the sciences—social or natural—do not challenge or defend the normative views we may hold.

This raises two questions: First, whether or not science by itself can address questions like “Is it permissible to destroy embryos for stem cell research?” If science cannot decide this matter, the question arises “Why can’t science answer this question?” Notice that both of these questions are addressed in philosophy. They are instances of the two kinds of questions by which we have defined the discipline. Of course at various times, including the present, some philosophers and scientists have tried to show that science can in fact answer at least some if not all normative questions. If it can do so, we will have eliminated a large number of questions that come under the broad heading of the first of the two sorts of questions that define philosophy. In addition to being a very controversial project, if successful, the attempt to ground ethical values on scientific facts is plainly an enterprise which would further vindicate science as the setter of philosophy’s agenda.

The nature of logical reasoning and its role in all the sciences also reflects the conception of philosophy as the study of questions the sciences can’t answer. All of the sciences, and especially the quantitative ones, rely heavily on the reliability of logical reasoning and deductively valid arguments; the sciences also rely on inductive arguments—ones that move from finite bodies of data to general theories. But none of the sciences can address directly the question of why arguments of the first kind are always reliable, and why we should employ arguments of the second kind in spite of the fact that they are not always reliable. The only way the sciences could vindicate their methods is by using those very methods themselves! After all they don’t have any other methods! But any such “vindication” of the methods of science would beg the question: Imagine accepting a promise to pay back a loan merely on the strength of a promise that one always keeps one’s promises. An argument like that relies on the very thing it sets out to justify; it “begs the question.” Insofar as there are questions about scientific method, these are ones the sciences themselves cannot answer.

What if There Are No Questions Left Over when Science Is Finished?

So our definition of philosophy does justice to the history of the sciences, and apparently to the division of labor between scientific and nonscientific inquiry about values and norms. And it makes sense of why logic, metaphysics, ethics and epistemology should constitute one discipline despite their heterogeneity: they all address questions raised, but as yet unanswered, by science. But if we consider the definition again, there is one challenge it must face. Recall, as we have defined philosophy, that the first set of questions philosophy deals with are the questions that science—physical, biological, social, behavioral—cannot answer now and perhaps may never be able to answer.

But suppose one holds that in fact there are no questions that the sciences cannot now or cannot eventually answer. One might claim that any question which is forever unanswerable is really a pseudo-question, a bit of meaningless noise masquerading as a legitimate question, like the question “Do green ideas sleep furiously?” or “When it’s noon GMT, what time is it on the Sun?” or “Did the universe and everything in it just double in size, charge, and every other physical magnitude?” or “How can we prove the universe and everything in it was not created five minutes ago?” Scientis...