The Meaning of It All - Article Example

Philosophy of Science Introduction In 1963, physicist Richard P. Feynman gave a series of speeches at a University in USA. These lectures were later published as “The Meaning of It All” (Feynman, pp. 20-22). In these lectures, Feynman discusses the impact that science has on society, the relationship between science and religion and the importance of doubt and uncertainty in science. He also addresses the question of “what is Science” by discussing several aspects of science, such as “science as a method of finding things out”, “science as the body of knowledge” obtained by this method, and “science as the ability to use the knowledge” (Feynman, pp. 20-22). Thus, acquired for practical purposes, this last aspect is more properly referred to as technology, but it is often confused with proper science in popular media. Considering the first two aspects of science discussed by Feynman, they are very closely related, indeed even complementary. At the root of both these aspects is epistemology, the theory of knowledge. What constitutes knowledge, how is it acquired and how do we advance it? What scientific knowledge is as contrasted to other types of knowledge? How does one decide the truth-value of a scientific hypothesis/theory? The philosophy of science prior to the 20th century The philosophy of science might be considered, after a fashion, to begin in Ancient Greece. Starting with Socrates and Plato, and finding its most influential exponent in Aristotle, the science of this period is mostly an intellectual exercise, relying on reason and logic at the expense of experience. Euclids Elements was, for centuries, considered as the pinnacle of scientific excellence. This view was held all throughout the Middle Ages and even the early Renaissance, until the arrival of Galileo Galilei on the scene. By choosing to experimentally test centuries-old hypotheses (and refute them), Galileo effectively marks the beginning of modern science. His influence on the subsequent philosophy of science cannot be overestimated. His work, and that of Newton, Leibniz, Huygens, lay the foundation for what would become the empiricist current in the philosophy of science, beginning with John Locke in the 17th century. Empiricism asserts that experience is not only the ultimate source of our knowledge but also of our concepts. For Locke, experience gradually limits the scope of what we can know, even as it helps us clarify those ideas which itself engenders. An empiricist philosopher of the 18th century, David Hume, took Lockes idea of skepticism of what can be known one step further, by showing that most of our more basic concepts have no proper grounding in experience. In particular, Hume also discarded the idea of induction – generalizing from particular to universal statements – a position we will find echoed in Karl Poppers philosophy of science. After the Galilean and Newtonian conceptual revolutions in science, progress was constant and gradual for the next couple of centuries, until the end of the 19th century. So much so that, at this time, physics at least was considered an almost complete science and no new upheavals were expected to occur. There were, of course, the occasional discrepancies between experiment and theory, but it was thought that no revolutionary ideas needed to be introduced to reconcile facts and theory. At the beginning of the 20th century, however, not one, but two such revolutions in physics took place: Einsteins Special and General Relativity and Quantum Theory, which changed not only our view of Nature, but also our ideas about Science itself. Logical positivism The philosophy of science becomes a bone fide subfield of philosophy for the first time with the logical positivism of the early 20th century. Following the remarkable success of Einsteins theory of relativity, and drawing inspiration from this success, at the core of logical positivism lays the idea of cognitively meaningful statements. These are statements which are true or false either because their truth-value can be determined a priori (analytic) or it can be determined by finding observations that would show it to be true or false (synthetic). This criterion of cognitive meaningfulness is called verificationism. Verification, in the case of an analytic statement, consists in logical proofs, while for a synthetic statement; it consists of observations and experiment. The verification of synthetic statements relies heavily on the principle of induction criticized by David Hume and, later on, Karl Popper. Other criticisms of logical positivism refer to its incapability to accommodate unverifiable but apparently scientific statements and concepts. In essence, logical positivism deals less with broad theories about the world, and more with predictions about observable facts. Popper and the problem of demarcation One of the best-known critics of logical positivism, Karl Popper defines the problem of demarcation as “the problem of finding a criterion which would enable us to distinguish between the empirical sciences on the one hand, and mathematics and logic as well as ‘metaphysical’ systems on the other” (Popper, pp. 11). Here, by “metaphysical systems”, Popper refers to non-science, as well as pseudo-science. The distinction here is a matter of method, rather than content. A non-science may make epistemological claims, but, unlike a pseudo-science, it does so without using a scientific language. Popper considered the problem of demarcation as “the source of nearly all the other problems of the theory of knowledge” (Popper, pp. 11), surpassing in importance the problem of logical induction, which, following Hume, he rejects. He also finds himself in opposition to the logical positivists of the early 20th century in discarding the idea – which relies on logical induction – that verifiability is a good criterion for demarcation. A theory, Popper argues, is should never really be confirmed by observation and experiment. After all, many pseudo-scientific theories can lay claims to such verification. Observations can always be interpreted as supporting a theory and explanations can be devised to accommodate experiments (Curd & Cover, pp. 3-10). Instead of the criterion of verifiability, Popper proposed his own criterion of falsifiability. According to this criterion, one should not look for observations that confirm the predictions a particular theory makes but, on the contrary, one should attempt to disprove that theory by producing observational evidence against it. The failure to produce such evidence grants additional life to a theory but it never fully confirms it. For this criterion to work, however, theories have to make specific and “bold” predictions (Popper, pp. 278). It is this bold prediction of Einsteins General Theory of Relativity and its subsequent confirmation by Eddingtons observation that recommended Einsteins theory as a genuine scientific theory, as opposed to the theories of Marx, Freud and Adler. Before a theory can be falsified, however, it must be put forward. On the subject of the inception of a scientific theory, Popper declines to comment. He does not consider this a subject for the “logical analysis of scientific knowledge” (Popper, pp. 7), but rather for the psychology of knowledge. One can draw a parallel between Poppers theory of scientific knowledge and Darwins theory of evolution through natural selection. It is important to keep in mind that, usually, the theory to be falsified does not live in a void. It has to compete with other rival theories for “survival” and “reproduction”. This diversity of theories mirrors the genetic diversity in a population, on which diversity natural selection can act. The way a theory survives is by failing to be falsified by observation or experiment. It can then go on and “reproduce”, i.e. it is ready to be subjected to another observational or experimental test. The competing theories, which are falsified and do not survive, are discarded. It is important not to take this analogy too seriously. The “population of theories” does not necessarily have to be a real population; indeed, in most cases, it is a “virtual” population, in the sense that only one theory is explicitly stated. However, since it is seldom stated completely there is a certain degree of freedom in the choice of parameters, and this provides the “genetic diversity” on which the “natural selection” of falsifiability can act. This view leads to a gradual progress in science from simple to more and more complex and interesting problems. Popper does not attempt to analyze the formulation of the first hypothesis, or set of hypotheses. His theory of knowledge cannot account, therefore for the very scientific revolution brought forth by Einstein that inspired Popper. Kuhn and the Scientific Revolution The view that exudes from Karl Poppers and the logical positivists outlook on science and the scientific methodology is one of a rational pursuit of truth, willingness to be proven wrong and adherence to the scientific method. This is, in a way, a dogmatic view of science, stemming from an unwillingness, or perhaps inability of the philosophers of science to apply the same empiricism they advocate for scientists in their own field. In addition, an American historian of science that upset this view of the scientific endeavor favored by Karl Popper and the others. In his 1962 book, “The Structure of Scientific Revolutions”, Thomas S. Kuhn introduced a new way of considering the field of science from the outside. He argued for an “observational” approach to the philosophy of science: he believed that by studying how scientists actually work important insights into the philosophy of science can be obtained. What Kuhn concluded was that, despite Poppers implication to the contrary, most scientific work falls into the category of what he calls normal science. This is characterized by a prevailing paradigm, even dogma, when there exists a broad consensus in the scientific community. This period in a science is usually characterized by problem solving. It is uneventful, relatively dogmatic, and undramatic. Punctuating these periods of normal science are the “scientific revolutions” Kuhn alludes to in the title of his book. These crises come about when a particular problem or set of problems continually resist solving. Slowly, the confidence in the prevailing paradigm under which these problems cannot be solved is beginning to wane. At this point, one or a handful of scientists can propose a new paradigm, which will be tested specifically on the problems that initiated the crisis. When a satisfactory paradigm has been found, this becomes the new norm and science returns to its “normality” period. This is the structure of a scientific revolution, in Kuhns view. It is important to note that, even though a particular science has gone through a revolution and a change of paradigm, the old paradigm need not be completely discarded, especially in such a mature science as Physics. It is true that Einsteins theory of relativity is such a revolutionary paradigm that it completely changes our notions of such basic concepts as space, time and simultaneity; but Newtonian physics has not been completely discarded. On the contrary, what Einsteins theory did was to more sharply define the boundaries of applicability of Newtonian physics and strengthen the confidence that physicists have in this theory within its domain of applicability. Thomas Kuhns paradigm shifting theory of the scientific endeavor generated much criticism, especially in the scientific community, but also among philosophers of science. Imre Lakatos attempted to reconcile Kuhns historical approach with a more methodological approach. Paul Feyerabend, on the other hand, completely dismissed any methodology in science, arguing for one rule only: “Anything goes.” One effect of the “Kuhnian revolution” was the emergence of a more pronounced emphasis put on the sociology of science. Science came to be regarded more and more as a social endeavor. The role of explanation in science Richard Feynman believed that science should concern itself to questions of “How?” but not with questions of “Why?” In other words, science should be looking to answer questions about how some particular phenomenon comes about, not why is it so. This last type of questions usually leads to an infinite regress, as people who have been interrogated by small children know very well. Feynmans approach contrasts the descriptive role of science to its explanatory role. In the empiricist tradition, the search for explanations runs the risk of running into metaphysical nonsense and it is therefore to be avoided. On the other hand, a mere description of a phenomenon does not really provide understanding. This comes when we know that something must happen, but not only when we know how it happens. The necessity that something must happen, however, must be a logical necessity. Scientists derive particular laws of nature from more general, universal laws (Keplers laws of planetary motion come from Newtons laws of motion and gravity). This explanatory tendency in sciences has led many scientists (physicists mainly) to claim that all biology can be reduced ultimately to chemistry and therefore to physics (chemistry has already been reduced to physics). Even more, neuroscientists believe that higher cognitive functions in humans are a result of neuronal activity in the brain and, therefore, have a biological basis. This leads, inexorably, to a physical account of consciousness, which is, needless to say, a subject that spans many scientific and non-scientific fields: biology, ethics and philosophy, religion, etc. Probability theory: the logic of science A particularly interesting approach to the philosophy of science is presented by E.T. Jaynes in his book on probability theory (Jaynes, pp. 11-13). This approach is not old; indeed Karl Popper addresses it in his book on the logic of science (Popper, pp. 19-21). It is the view that should resonate with Popper in the sense that it does not lay any claim of verificationism, i.e. it does not hold that a theory can be proven by observation. What this approach does is that it quantifies the confidence that a scientist has in a theory, and it offers a mathematical formula (Bayes formula) for “updating” that confidence in the light of new data, e.g. an experiment that fails to falsify the theory. In this view, a hypothesis is tested observationally and experimentally and, if it is not falsified, its “truth probability” is updated. It is important to note that the hypothesis is not only tested, but it is also compared to another competing hypothesis, or set of hypotheses. Another important and somewhat controversial feature of this approach is the inclusion of a “prior probability”, that is a probability assigned to the hypothesis in question before any observation is made or experiment is performed. This last feature gives a distinctly subjective flavor to this approach, and it has been criticized on this ground. Conclusions The philosophy of science has gone through multiple phases over the course of time. From the purely intellectual exercise that science was considered from antiquity to the 16th century, through the purely empiricist phase of the 16th and 17th century and to the plethora of different approaches that the 20th century has engendered, the philosophy of science seems to have always taken its cue from science and trailing just a few steps behind it. A quote often attributed to Richard Feynman gives one pause: “Philosophy of science is about as useful to scientists as ornithology is to birds” (Feynman, pp. 23-25). Works Cited Curd, Martin and Cover, J.A. Philosophy of Science: the central issues. W.W. Norton, 1998. Feynman, Richard P. The Meaning of It All. Addison-Wesley, 1999. Jaynes, Edwin T. Probability Theory: The Logic of Science. Cambridge University Press, 2003. Kuhn, T.S. The Structure of Scientific Revolutions. University of Chicago Press, 1996. Popper, Karl. The Logic of Scientific Discovery. Routledge, 2002. Read More