Arguing About Science

Alexander Bird, James Ladyman, Alexander Bird, James Ladyman

• Publisher: Routledge
• Year: 2012
• ISBN:
  9781135695156
• Edition: 1
• Topic: Filosofia
• Subtopic: Storia e teoria della filosofia

Arguing About Science is an outstanding, engaging introduction to the essential topics in philosophy of science, edited by two leading experts in the field. This exciting and innovative anthology contains a selection of classic and contemporary readings that examine a broad range of issues, from classic problems such as scientific reasoning; causation; and scientific realism, to more recent topics such as science and race; forensic science; and the scientific status of medicine.

The editors bring together some of the most influential contributions of famous philosophers in the field, including John Stuart Mill and Karl Popper, as well as more recent extracts from philosophers and scientists such as Ian Hacking, Stephen Jay Gould, Bas van Fraassen, Nancy Cartwright, and John Worrall. The anthology is organised into nine clear sections:

• science, non science and pseudo-science
• race, gender and science
• scientific reasoning
• scientific explanation
• laws and causation
• science and medicine
• probability and forensic science
• risk, uncertainty and science policy
• scientific realism and anti-realism.

The articles chosen are clear, interesting, and free from unnecessary jargon. The editors provide lucid introductions to each section in which they provide an overview of the debate, as well as suggestions for further reading.

PART ONE

What is science?

INTRODUCTION TO PART ONE

WE BEGIN WITH the most fundamental question in the philosophy of science, and it is one that concerns many people other than philosophers. The definition of science matters to education, public policy, medicine, religion and the law. Governments must draw upon genuine science when making decisions, must license only those medicines that have passed scientific tests and standards of evidence, and must ensure that children are taught science not pseudo-science in areas such as biology, cosmology, medicine and physics. Courts must often take the opinion of scien-tific expert witnesses when considering forensic evidence. Where laws provide for the separation of church and state, the definition of science may be important because there are religiously-inspired bodies of teaching for which scientific status is claimed. When we consider the social sciences, the definition of science becomes ethically and politically important. If social scientists use concepts such as ‘race’, ‘gender’, ‘sexuality’ and so on, it is important that how those concepts are defined is made clear so that it can be established whether or not their use is properly scientific, or in fact just a vehicle for an ideological agenda. Similarly, when policymakers claim to be using ‘evidence-based’ decision making we need to be able to investigate the dividing line between the scientific content of their deliberations and the influence of vested interests and ideology in its interpretation.

Philosophers of science and scientists investigate these issues and there is no sharp dividing line between theoretical science and philosophical inquiry in it. Disputes about the proper definition of terms, such as ‘species’, ‘gene’ or ‘fitness’, and arguments about the right methodology to use in interpreting data, are an important part of everyday scientific life. When there are profound economic and social consequences at stake, the debate about what is properly scientific becomes of interest to everyone in society. Almost everyone has an opinion about anthropogenic climate change, for example. The famous hockey stick graph of the average temperature in the Northern hemisphere has become the subject of everyday discussion, yet is a fairly sophisticated statistical construction that shows departures from an average plotted against time. Even the fairly elementary science behind it requires a level of mathematical statistics that some people never learn, applied to measurements that we will not perform ourselves. In this, as in many issues, the definition of science matters because we need to defer to scientific experts in arriving at our own beliefs.

In everyday parlance science is associated with logic, with empirical investigation, and with reason and rationality. For some, these connotations are overwhelmingly positive; for others, all harbour dangers and threaten to overlook important things about human existence and to denude the world of meaning. There was a reactionagainst science in the Romantic movement of the late eighteenth and early nineteenth centuries, and there have been similar such criticisms of science ever since. The original meaning of the term ‘science’ is from the Latin scientia meaning knowledge, where knowledge is not the same thing as true belief. There is much debate about the nature of knowledge among philosophers, but it is always taken to be distinct from true belief that is somehow accidental or the result of completely spurious reasoning. To know is to be possessed of evidence, justification and reason; or at least to be reliable or connected to the world or the truth in the right kind of way.

It is important to note that there is a lot of bona fide knowledge that is not scientific. The science/non-science distinction does not track the difference between rational enquiry and non-rational enquiry either. A person can be rational, making deductions and inferences, and use empirical methods, measuring, gathering and collating data, without being part of science (though it may be argued that science is continuous with, and has its origins in, good everyday reasoning). Philosophers of science are often interested in the difference between science and pseudo-science, and usually regard the former as good and the latter as bad, but this should not be taken to imply the lack of a critical attitude to science itself. There is good and bad science and shades of grey in between, and much contemporary science is hopefully to be corrected and refined in the future. The word ‘scientist’ was not used in its contemporary sense until the nineteenth century when the emergence of scientific institutions and disciplines had become mature and established after their beginnings in the seventeenth century. Science is an emergent historical phenomenon and, according to a widely held though contested view, came into being, from ancient and medieval roots, in the Scientific Revolution in Europe around the mid-seventeenth century. There are two vital facts to know about this period.

The first is that the larger Scientific Revolution had as its most important component the Copernican Revolution, when the view that the Earth is the centre of the universe (geocentrism) was replaced by the hypothesis that it orbits the Sun along with the other planets (heliocentrism). This was not just a dispute about astronomy, since the hypothesis that the Earth is at the centre of the universe was essential to the medieval orthodoxy of Aristotelian physics, especially to the explanation of gravity. It was also linked to the understanding of heaven, hell, and the place of human beings in the cosmos. The Catholic Church had a very great investment in the established tradition of scholastic Aristotelian natural philosophy, and the former’s intellectual authority had been challenged by the thinkers of the Reformation. Hence, when Galileo publicly advocated Copernicanism, this eventually led to his trial and imprisonment. Eventually, even the Catholic Church came to accept Copernicanism. A similarly heated conflict between science and religion would not arise again until Darwin’s theory of evolution by natural selection challenged the idea that each species on the Earth was individually created by God.

The second feature of the Scientific Revolution that must be mentioned even in the briefest of histories is that there was an extraordinary growth in knowledge in numerous domains in a relatively short period of time, so that the term ‘revolution’ isnot a misnomer. A standard list of scientific advances of the period would probably include:

●Kepler’s laws of planetary motion (1609)

●Newton’s mechanics (1687)

●the first law of ideal gases (Robert Boyle, 1662)

●the circulation of the blood by the heart (William Harvey, 1628).

All but the third involved the abandonment of entrenched orthodoxies. Kepler overthrew the ancient idea that all motion in the perfect heavenly realm was composed of circular movements. Newton overthrew the recent orthodoxy that all motion was caused by contact, with his mysterious but mathematically precise gravitational force. Harvey rejected the orthodoxy originating with Galen that blood is created by the liver and that the heart exists solely to produce heat. It is often argued that there is something inherently scientific about scepticism towards received ideas. We will come back to the idea that science proceeds by the continual questioning and overthrowing of established ideas below, since it is central to the first account we will consider of the nature of science.

There are two reasons why scientists and others need an account of the nature of science. The first is that people often want to criticize particular theories or research programmes as poor science by invoking criteria for good science, and the latter are in part derived from and definitive of what they think science is. The second is that people often want to argue that particular theories, research programmes and even whole areas of activity are not scientific at all. This judgement can clearly only be defended by appeal to conditions that must be satisfied for something to be scientific. Such conditions are called necessary conditions. For example, a necessary condition for a shape to be a square is that is has four sides. Sometimes a necessary condition is also a sufficient condition. A sufficient condition for a shape to be a triangle is that it has three (straight) sides. This is also necessary because any shape lacking three sides is not a triangle. But having four sides is not sufficient for being a square, because squares must have four equal sides and four equal internal angles. We have here two necessary conditions and they are jointly sufficient but not each individually sufficient. The ideal endpoint of our inquiry is that we arrive at a set of necessary conditions for something to be science and that they are also together sufficient. We would have then a definition of ‘science’ and we could use it to tell science apart from pseudo-science (and bad science). The question of how to separate science from ‘pseudo-science’ is ‘the demarcation problem’.

Conditions for science, often known as d emarcation criteria, may be applied to different things. Roughly speaking there are three plausible candidates, and accounts of the nature of science can be considered for what they say about each and the relative emphasis they place on them. The first candidate is the theories that are the output of science, the second is the methods by which the theories are produced, and the third is the character and disposition of the scientists who produce them.

It will help to have an example in mind, and we shall take Newtonian mechanics. It introduced the contemporary understanding of mass, force and velocity; it consisted of three laws of motion and a law of universal gravitation; it successfully unified Kepler’s laws of planetary motion, Galileo’s laws of free-fall and the pendulum; it explained the tides in terms of the Moon’s gravity; and it predicted the return of Halley’s comet, the existence of Neptune and the fact that the Earth is not quite spherical but bulged at the equator.

If we are to put theories at the centre of our account of science, we might consider the above good features of Newtonian mechanics, and generalize arguing that proper scientific theories must be mathematically precise, have a few simple laws that unify diverse phenomena, and be predictive in the sense of implying facts that we have not yet observed. If we focus on the method by which the theories are produced then we will cite the fact that Newton sought to recover by a mathematical analysis the known laws that describe the motions of the planets and so arrived at his inverse square law of gravitation. Those laws themselves were arrived at after Kepler had considered a vast and accurate body of astronomical data about the observed positions of the planets in the night sky at different times. Newton himself claimed to have inferred his laws from the data and not to have made hypotheses, and his example led others to advocate a theory of the scientific method according to which theories must always be arrived at this way. Finally, if we focus on the scientist himself we will emphasize Newton’s mathematical genius, his obsessive character and rigorous approach to foundational matters, and the role of the individual genius working largely alone but building on the work of the scientists who had gone before him, especially, in this case, Galileo and Kepler.

The problem with focusing on theories is that science contains very heterogeneous theories covering a vast range of subject matters, and these theories change over time, so it would be rash to associate science in general with the characteristics of particular theories. So, for example, Darwin’s theory was not at all mathematical and nor was it, originally, especially precisely predictive. It is often said that there are no strict mathematical laws outside of physics and, although that may be an exaggeration, there is certainly a lot of difference between theories in physics and theories in the other physical and social sciences. When it comes to the characteristics of scientists they too vary greatly: some being highly collaborative and others loners, some being very open-minded while others cling to their preferred theory with the conviction of a zealot, and some being mathematical geniuses while others are meticulous observers and field workers. Nonetheless, many philosophers of science have argued that scientists must have certain qualities, or that the scientific community must be organized in a particular way. Most accounts of the nature of science have something to say about the theories, methods and virtues of good scientists, but it is probably fair to say that most have focused on the scientific method. For many people, it is its methods that fundamentally distinguish science, making it a self-correcting and successful form of inquiry that is unrivalled.

Our readings begin with a classic chapter on the demarcation of science from non-science from Karl Popper. No philosopher has had such an influence on what scientists themselves say about science since, and although his ideas were developed in the mid-twentieth century, his influence remains strong today (for example, a recent book on philosophy of science by the physicist David Deutsch has scant regard for any philosopher other than Popper). The fundamental idea he introduced was a negative one. Science is not about proof and certainty, according to Popper; it is about refutation and conjecture. He called this account of the methodology of science ‘critical rationalism’. He ar...