Philosophy of science
Philosophy of science is a branch of philosophy concerned with the foundations, methods, and implications of science. The central questions of this study concern what qualifies as science, the reliability of scientific theories, and the ultimate purpose of science. This discipline overlaps with metaphysics, ontology, and epistemology, for example, when it explores the relationship between science and truth.
There is no consensus among philosophers about many of the central problems concerned with the philosophy of science, including whether science can reveal the truth about unobservable things and whether scientific reasoning can be justified at all. In addition to these general questions about science as a whole, philosophers of science consider problems that apply to particular sciences such as biology or physics. Some philosophers of science also use contemporary results in science to reach conclusions about philosophy itself.
While the relevant history of philosophy dates back at least to the time of Aristotle, philosophy of science emerged as a distinct discipline only in the middle of the 20th century in the wake of the logical positivism movement, which aimed to formulate criteria for ensuring all philosophical statements' meaningfulness and objectively assessing them. Thomas Kuhn's book The Structure of Scientific Revolutions brought the word "paradigm" into the mainstream, meaning the set of practices that define a scientific discipline in a particular period. In this book, Kuhn challenged the established view of "Scientific progress as a gradual, cumulative acquisition of knowledge based on rationally chosen experimental frameworks".
Today, some thinkers seek to ground science in axiomatic assumptions, such as the uniformity of nature. Many philosophers of science, however, take a coherentist approach to science, in which a theory is validated if it makes sense of observations as part of a coherent whole. Still others, and Paul Feyerabend in particular, argue that there is no such thing as the "scientific method", so all approaches to science should be allowed, including explicitly supernatural ones. (Feyerabend's view is in the minority among philosophers of science.) Another approach to thinking about science is to study how knowledge is created from a sociological perspective, represented by scholars like David Bloor and Barry Barnes. Finally, there is a tradition in Continental philosophy which approaches science from the perspective of a rigorous analysis of human experience.
Philosophy of the particular sciences ranges from questions about the nature of time raised by Einstein's general relativity, to the implications of economics for public policy. A central theme is whether one scientific discipline can be reduced to the terms of another. That is, can chemistry be reduced to physics, or can sociology be reduced to individual psychology? The general questions of philosophy of science also arise with greater specificity in the particular sciences. For instance, the question of the validity of scientific reasoning is seen in a different guise in the foundations of statistics. The question of what counts as science and what should be excluded arises as a life-or-death matter in the philosophy of medicine. Additionally, the philosophies of biology, psychology, and the social sciences explore whether the scientific studies of human nature can achieve objectivity or are inevitably shaped by values and social relations.
- 1 Introduction
- 2 History
- 3 Current approaches
- 4 Other topics
- 5 Philosophy of particular sciences
- 6 See also
- 7 References
- 8 Cited texts
- 9 Further reading
- 10 External links
Distinguishing between science and non-science is referred to as the demarcation problem. For example, should psychoanalysis be considered science? How about so-called creation science, the inflationary multiverse hypothesis, or macroeconomics? Karl Popper called this the central question in the philosophy of science. However, no unified account of the problem has won acceptance among philosophers, and some regard the problem as unsolvable or uninteresting.
Early attempts by the logical positivists grounded science in observation while non-science was non-observational and hence meaningless. Popper argued that the central property of science is falsifiability. That is, every genuinely scientific claim is capable of being proven false, at least in principle.
An area of study or speculation that masquerades as science in an attempt to claim a legitimacy that it would not otherwise be able to achieve is referred to as pseudoscience, fringe science, or junk science. Physicist Richard Feynman coined the term "cargo cult science" for cases in which researchers believe they are doing science because their activities have the outward appearance of it but actually lack the "kind of utter honesty" that allows their results to be rigorously evaluated. Various types of commercial advertising, ranging from hype to fraud, may fall into these categories.
A closely related question is what counts as a good scientific explanation. In addition to providing predictions about future events, society often takes scientific theories to provide explanations for events that occur regularly or have already occurred. Philosophers have investigated the criteria by which a scientific theory can be said to have successfully explained a phenomenon, as well as what it means to say a scientific theory has explanatory power.
One early and influential theory of scientific explanation is the Deductive-Nomological model. It says that a successful scientific explanation must deduce the occurrence of the phenomena in question from a scientific law. This view has been subjected to substantial criticism, resulting in several widely acknowledged counterexamples to the theory. It is especially challenging to characterize what is meant by an explanation when the thing to be explained cannot be deduced from any law because it is a matter of chance, or otherwise cannot be perfectly predicted from what is known. Wesley Salmon developed a model in which a good scientific explanation must be statistically relevant to the outcome-to-be-explained. Others have argued that the key to a good explanation is unifying disparate phenomena or providing a causal mechanism.
Although it is often taken for granted, it is not at all clear how one can infer the validity of a general statement from a number of specific instances or infer the truth of a theory from a series of successful tests. For example, a chicken observes that each morning the farmer comes and gives it food, for hundreds of days in a row. The chicken may therefore use inductive reasoning to infer that the farmer will bring food every morning. However, one morning, the farmer comes and kills the chicken. How is scientific reasoning more trustworthy than the chicken's reasoning?
Any argument in favor of induction must avoid the problem of the criterion, in which any justification must in turn be justified, resulting in an infinite regress. The regress argument has been used to justify one way out of the infinite regress, foundationalism. Foundationalism claims that there are some basic statements that do not require justification. Both induction and falsification are forms of foundationalism in that they rely on basic statements that derive directly from immediate sensory experience.
Another approach is to acknowledge that induction cannot achieve certainty, but observing more instances of a general statement can at least make the general statement more probable. So the chicken would be right to conclude from all those mornings that it is likely the farmer will come with food again the next morning, even if it cannot be certain. However, there remain difficult questions about what precise probability any given evidence justifies putting on the general statement. One way out of these particular difficulties is to declare that all beliefs about scientific theories are subjective, or personal, and correct reasoning is merely about how evidence should change one's subjective beliefs over time.
Some argue that what scientists do is not inductive reasoning at all but rather abductive reasoning, or inference to the best explanation. In this account, science is not about generalizing specific instances but rather about hypothesizing explanations for what is observed. As discussed in the previous section, it is not always clear what is meant by the "best explanation." Ockham's razor, which counsels choosing the simplest available explanation, thus plays an important role in some versions of this approach. To return to the example of the chicken, would it be simpler to suppose that the farmer cares about it and will continue taking care of it indefinitely or that the farmer is fattening it up for slaughter? Philosophers have tried to make this heuristic principle more precise in terms of theoretical parsimony or other measures. Yet, although various measures of simplicity have been brought forward as potential candidates, it is generally accepted that there is no such thing as a theory-independent measure of simplicity. In other words, there appear to be as many different measures of simplicity as there are theories themselves, and the task of choosing between measures of simplicity appears to be every bit as problematic as the job of choosing between theories.
Observation inseparable from theory
When making observations, scientists look through telescopes, study images on electronic screens, record meter readings, and so on. Generally, on a basic level, they can agree on what they see, e.g., the thermometer shows 37.9 degrees C. But, if these scientists have different ideas about the theories that have been developed to explain these basic observations, they may disagree about what they are observing. For example, before Albert Einstein's general theory of relativity, observers would have likely interpreted the image at left as five different objects in space. In light of that theory, however, astronomers will tell you that is actually only two objects, one in the center and four different images of the same object around the sides. Alternatively, if other scientists suspect that something is wrong with the telescope and only one object is actually being observed, they are operating under yet another theory. Observations that cannot be separated from theoretical interpretation are said to be theory-laden.
All observation involves both perception and cognition. That is, one does not make an observation passively, but rather is actively engaged in distinguishing the phenomenon being observed from surrounding sensory data. Therefore, observations are affected by one's underlying understanding of the way in which the world functions, and that understanding may influence what is perceived, noticed, or deemed worthy of consideration. In this sense, it can be argued that all observation is theory-laden.
Moreover, most scientific observation must be done within a theoretical context in order to be useful. For example, when one observes a measured increase in temperature with a thermometer, that observation is based on assumptions about the nature of temperature and its measurement, as well as assumptions about how the thermometer functions. Such assumptions are necessary in order to obtain scientifically useful observations (such as, "the temperature increased by two degrees").
The purpose of science
Should science aim to determine ultimate truth, or are there questions that science cannot answer? Scientific realists claim that science aims at truth and that one ought to regard scientific theories as true, approximately true, or likely true. Conversely, scientific anti-realists argue that science does not aim (or at least does not succeed) at truth, especially truth about unobservables like electrons or other universes. Instrumentalists argue that scientific theories should only be evaluated on whether they are useful. In their view, whether theories are true or not is beside the point, because the purpose of science is to make predictions and enable effective technology.
Realists often point to the success of recent scientific theories as evidence for the truth (or near truth) of current theories. Antirealists point to either the many false theories in the history of science, epistemic morals, the success of false modeling assumptions, or widely termed postmodern criticisms of objectivity as evidence against scientific realism. Antirealists attempt to explain the success of scientific theories without reference to truth. Some antirealists claim that scientific theories aim at being accurate only about observable objects and argue that their success is primarily judged by that criterion.
Values and science
If it is unclear what counts as science, how the process of confirming theories works, and what the purpose of science is, there is considerable scope for values and other social influences to shape science. Indeed, values can play a role ranging from determining which research gets funded to influencing which theories achieve scientific consensus. Feminist philosophers of science, sociologists of science, and others explore how social values affect science.
The origins of philosophy of science trace back to Plato and Aristotle who distinguished the forms of approximate and exact reasoning, set out the threefold scheme of abductive, deductive, and inductive inference, and also analyzed reasoning by analogy. The eleventh century Arab polymath Ibn al-Haytham (known in Latin as Alhazen) conducted his research in optics by way of controlled experimental testing (which he called in Arabic: al-i'tibar) and was guided in this by geometrical studies, especially in his investigations in catoptrics and dioptrics.  Roger Bacon (1214–1294), a Franciscan friar, English thinker, and experimenter, is recognized by many to be the father of modern scientific method. His view that mathematics was essential to a correct understanding of natural philosophy was considered to be 400 years ahead of its time.
In the modern period of science, Francis Bacon was a seminal figure at the time of the Scientific Revolution. In his work Novum Organum (1620) – a reference to Aristotle's Organon – Bacon outlined a new system of logic to improve upon the old philosophical process of syllogism. Bacon's method relied on experimental histories to eliminate alternative theories. Then, in 1637, René Descartes established a new framework for scientific method's guiding principles in his treatise, Discourse on Method, advocating rationalism. The writings of Alhazen, Bacon and Descartes are considered critical in the historical development of the modern scientific method, as are those of John Stuart Mill. David Hume expressed skepticism about the ability of science to determine causality and gave a definitive formulation of the problem of induction.
Instrumentalism became popular among physicists around the turn of the 20th century, after which logical positivism defined the field for several decades. Logical positivism accepts only testable statements as meaningful, rejects metaphysical interpretations, and embraces verificationism (a set of theories of knowledge that combines logicism, empiricism, and linguistics to ground philosophy on a basis consistent with examples from the empirical sciences). Seeking to overhaul all of philosophy and convert it to a new scientific philosophy, the Berlin Circle and the Vienna Circle propounded logical positivism in the late 1920s.
Interpreting Ludwig Wittgenstein's early philosophy of language, logical positivists identified a verifiability principle or criterion of cognitive meaningfulness. From Bertrand Russell's logicism they sought reduction of mathematics to logic. They also embraced Russell's logical atomism, Ernst Mach's phenomenalism—whereby the mind knows only actual or potential sensory experience, which is the content of all sciences, whether physics or psychology—and Percy Bridgman's operationalism. Thereby, only the verifiable was scientific and cognitively meaningful, whereas the unverifiable was unscientific, cognitively meaningless "pseudostatements"—metaphysical, emotive, or such—not worthy of further review by philosophers, who were newly tasked to organize knowledge rather than develop new knowledge.
Logical positivism became famed for vigorous scientific antirealism to purge science of talk about unobservable things—including causality, mechanism, and principles—although that goal has been exaggerated[who said this?]. Still, talk of such unobservables could be allowed as metaphorical—direct observations viewed in the abstract—or at worst metaphysical or emotional. Theoretical laws would be reduced to empirical laws, while theoretical terms would garner meaning from observational terms via correspondence rules. Mathematics in physics would reduce to symbolic logic via logicism, while rational reconstruction would convert ordinary language into standardized equivalents, all networked and united by a logical syntax. A scientific theory would be stated with its method of verification, whereby a logical calculus or empirical operation could verify its falsity or truth.
In the late 1930s, logical positivists fled Germany and Austria for Britain and America. By then, many had replaced Mach's phenomenalism with Otto Neurath's physicalism, and Rudolf Carnap had sought to replace verification with simply confirmation. With World War II's close in 1945, logical positivism became milder, logical empiricism, led largely by Carl Hempel, in America, who expounded the covering law model of scientific explanation as a way of identifying the logical form of explanations without any reference to the suspect notion of "causation". The logical positivist movement became a major underpinning of analytic philosophy, and dominated Anglosphere philosophy, including philosophy of science, while influencing sciences, into the 1960s. Yet the movement failed to resolve its central problems, and its doctrines were increasingly assaulted. Nevertheless, it brought about the establishment of philosophy of science as a distinct subdiscipline of philosophy, with Carl Hempel playing a key role.
In his landmark 1962 book The Structure of Scientific Revolutions Thomas Kuhn crystallized the reaction against logical positivism. He argued that the process of observation and evaluation take place within a paradigm. By "paradigm" he meant, essentially, a logically consistent "portrait" of the world, one that involves no logical contradictions and that is consistent with observations that are made from its point of view. He described the process of observation and "puzzle solving" which takes place within a paradigm, which he called "normal science." He also explained how one paradigm can overtake another, which process he termed a paradigm shift.
Kuhn denied that it is ever possible to isolate the hypothesis being tested from the influence of the theory in which the observations are grounded, and he argued that it is not possible to evaluate competing paradigms independently. More than one logically consistent construct can paint a usable likeness of the world, but there is no common ground from which to pit two against each other, theory against theory. Neither is a standard by which the other can be judged, so there is no clear way to measure scientific progress.
For Kuhn, the choice of paradigm was sustained by, but not ultimately determined by, logical processes. An individual's choice between paradigms involves setting two or more "portraits" against the world and deciding which likeness is most promising. In the case of a general acceptance of one paradigm or another, Kuhn believed that it represented the consensus of the community of scientists. Acceptance or rejection of some paradigm is, he argued, a social process as much as a logical process. Kuhn's position, however, is not one of relativism. According to Kuhn, a paradigm shift will occur when a significant number of observational anomalies in the old paradigm have made the new paradigm more useful. That is, the choice of a new paradigm is based on observations, even though those observations are made against the background of the old paradigm.
Some thinkers seek to articulate axiomatic assumptions on which science may be based, a form of foundationalism. Proponents argue that these assumptions are reasonable and necessary for practicing science. For instance, Hugh Gauch argues that science presupposes that "the physical world is orderly and comprehensible." Likewise, biologist Stephen Jay Gould cites the constancy of nature's laws as an assumption which a scientist should assume before proceeding to do geology. In this view, the uniformity of scientific laws is an unprovable postulate which enables scientists to extrapolate into the unobservable past. In other words, the constancy of natural laws must be assumed in order to meaningfully study the past.
In contrast to the view that science rests on foundational assumptions, coherentism asserts that statements are justified by being a part of a coherent system. Or, rather, individual statements cannot be validated on their own: only coherent systems can be justified. A prediction of a transit of Venus is justified by its being coherent with broader beliefs about celestial mechanics and earlier observations. As explained above, observation is a cognitive act. That is, it relies on a pre-existing understanding, a systematic set of beliefs. An observation of a transit of Venus requires a huge range of auxiliary beliefs, such as those that describe the optics of telescopes, the mechanics of the telescope mount, and an understanding of celestial mechanics. If the prediction fails and a transit is not observed, that is likely to occasion an adjustment in the system, a change in some auxiliary assumption, rather than a rejection of the theoretical system.
In fact, according to the Duhem-Quine thesis, after Pierre Duhem and Willard Van Orman Quine, it is impossible to test a theory in isolation. One must always add auxiliary hypotheses in order to make testable predictions. For example, to test Newton's Law of Gravitation in the solar system, one needs information about the masses and positions of the Sun and all the planets. Famously, the failure to predict the orbit of Uranus in the 19th century led not to the rejection of Newton's Law but rather to the rejection of the hypothesis that the solar system comprises only seven planets. The investigations that followed led to the discovery of an eighth planet, Neptune. If a test fails, something is wrong. But there is a problem in figuring out what that something is: a missing planet, badly calibrated test equipment, an unsuspected curvature of space, or something else.
One consequence of the Duhem-Quine thesis is that one can make any theory compatible with any empirical observation by the addition of a sufficient number of suitable ad hoc hypotheses. Karl Popper accepted this thesis, leading him to reject naïve falsification. Instead, he favored a "survival of the fittest" view in which the most falsifiable scientific theories are to be preferred.
Austrian philosopher of science Paul Feyerabend argued that no description of scientific method could possibly be broad enough to encompass all the approaches and methods used by scientists. He claimed there are no useful and exception-free methodological rules governing the progress of science. Feyerabend objected to prescriptive scientific method on the grounds that any such method would stifle and cramp scientific progress. Feyerabend claimed, "the only principle that does not inhibit progress is: anything goes."
Feyerabend felt that science started as a liberating movement, but over time it had become increasingly dogmatic and rigid, and therefore had become increasingly an ideology, and, despite its successes, science had started to attain some oppressive features. He argued it was not possible to come up with an unambiguous way to distinguish science from religion, magic, or mythology. He felt the exclusive dominance of science as a means of directing society was authoritarian and ungrounded. Promulgation of this epistemological anarchism earned Feyerabend the title of "the worst enemy of science" from his detractors.
Sociology of scientific knowledge
'A paradigm is what the members of a community of scientists share, and, conversely, a scientific community consists of men who share a paradigm'. On Kuhn's account, science can be done only as a part of a community, and is inherently a communal activity. The fundamental difference between science and other disciplines is in the way in which the communities function. Others, especially Feyerabend and some post-modernist thinkers, have argued that there is insufficient difference between social practices in science and other disciplines to maintain this distinction. It is apparent that social factors play an important and direct role in scientific method, but that they do not serve to differentiate science from other disciplines. Furthermore, although on this account science is socially constructed, it does not follow that reality is a social construct. (See Science studies and the links there.)
There are, however, those who maintain that scientific reality is indeed a social construct, to quote Quine:
Physical objects are conceptually imported into the situation as convenient intermediaries not by definition in terms of experience, but simply as irreducible posits comparable, epistemologically, to the gods of Homer ... For my part I do, qua lay physicist, believe in physical objects and not in Homer's gods; and I consider it a scientific error to believe otherwise. But in point of epistemological footing, the physical objects and the gods differ only in degree and not in kind. Both sorts of entities enter our conceptions only as cultural posits
The public backlash of scientists against such views, particularly in the 1990s, came to be known as the science wars.
A major development in recent decades has been the study of the formation, structure, and evolution of scientific communities by sociologists and anthropologists including David Bloor, Barry Barnes, Harry Collins, Michel Callon, Bruno Latour, John Law, Anselm Strauss, Lucy Suchman, and others. Concepts and methods (such as rational choice, social choice or game theory) from economics have also been applied for understanding the efficiency of scientific communities in the production of knowledge. This interdisciplinary field has come to be known as Science and Technology Studies. Here the approach to the philosophy of science is to study how scientific communities actually operate.
Philosophers in the Continental philosophical tradition are not traditionally categorized as philosophers of science. However, they have much to say about science, some of which has anticipated themes in the analytical tradition. For example, Nietzsche advanced the thesis in his "The Genealogy of Morals" that the motive for search of truth in sciences is a kind of ascetic ideal.
In general, science in continental philosophy is viewed from a world-historical perspective. One of the first philosophers who supported this view was Georg Wilhelm Friedrich Hegel. Philosophers such as Pierre Duhem and Gaston Bachelard also wrote their works with this world-historical approach to science, predating Kuhn by a generation or more. All of these approaches involve a historical and sociological turn to science, with a priority on lived experience (a kind of Husserlian "life-world"), rather than a progress-based or anti-historical approach as done in the analytic tradition. This emphasis can be traced through Edmund Husserl's phenomenology, the late works of Merleau-Ponty (Nature: Course Notes from the Collège de France, 1956–1960), and Martin Heidegger's hermeneutics.
The largest effect on the continental tradition with respect to science was Martin Heidegger's critique of the theoretical attitude in general which of course includes the scientific attitude. For this reason the Continental tradition has remained much more skeptical of the importance of science in human life and philosophical inquiry. Nonetheless, there have been a number of important works: especially a Kuhnian precursor, Alexandre Koyré. Another important development was that of Foucault's analysis of the historical and scientific thought in The Order of Things and his study of power and corruption within the "science" of madness. Post-Heideggerian authors contributing to the Continental philosophy of science in the second half of the 20th century include Jürgen Habermas (e.g., "Truth and Justification", 1998), Carl Friedrich von Weizsäcker ("The Unity of Nature", 1980), and Wolfgang Stegmüller ("Probleme und Resultate der Wissenschafttheorie und Analytischen Philosophie", 1973–1986).
Analysis is the activity of breaking an observation or theory down into simpler concepts in order to understand it. Analysis is as essential to science as it is to all rational activities. For example, the task of describing mathematically the motion of a projectile is made easier by separating out the force of gravity, angle of projection and initial velocity. After such analysis it is possible to formulate a suitable theory of motion.
Reductionism can refer to one of several philosophical positions related to this approach. One type of reductionism is the belief that all fields of study are ultimately amenable to scientific explanation. Perhaps a historical event might be explained in sociological and psychological terms, which in turn might be described in terms of human physiology, which in turn might be described in terms of chemistry and physics. Daniel Dennett invented the term greedy reductionism to describe the assumption that such reductionism was possible. He claims that it is just 'bad science', seeking to find explanations which are appealing or eloquent, rather than those that are of use in predicting natural phenomena.
A broad issue affecting the neutrality of science concerns the areas which science chooses to explore, that is, what part of the world and man is studied by science. Philip Kitcher in his "Science, Truth, and Democracy" argues that scientific studies that attempt to show one segment of the population as being less intelligent, successful or emotionally backward compared to others have a political feedback effect which further excludes such groups from access to science. Thus such studies undermine the broad consensus required for good science by excluding certain people, and so proving themselves in the end to be unscientific.
Philosophy of particular sciences
There is no such thing as philosophy-free science; there is only science whose philosophical baggage is taken on board without examination.—Daniel Dennett, Darwin's Dangerous Idea, 1995
In addition to addressing the general questions regarding science and induction, many philosophers of science are occupied by investigating foundational problems in particular sciences. They also examine the implications of particular sciences for broader philosophical questions. The late 20th and early 21st century has seen a rise in the number of practitioners of philosophy of a particular science.
Philosophy of statistics
The problem of induction discussed above is seen in another form in debates over the foundations of statistics. The standard approach to statistical hypothesis testing avoids claims about whether evidence supports a hypothesis or makes it more probable. Instead, the typical test yields a p-value, which is the probability of the evidence being such as it is, under the assumption that the hypothesis being tested is true. If the p-value is too low, the hypothesis is rejected, in a way analogous to falsification. In contrast, Bayesian inference seeks to assign probabilities to hypotheses. Related topics in philosophy of statistics include probability interpretations, overfitting, and the difference between correlation and causation.
Philosophy of mathematics
Philosophy of mathematics is concerned with the philosophical foundations and implications of mathematics. The central questions are whether numbers, triangles, and other mathematical entities exist independently of the human mind and what is the nature of mathematical propositions. Is asking whether "1+1=2" is true fundamentally different from asking whether a ball is red? Was calculus invented or discovered? A related question is whether learning mathematics requires experience or reason alone. What does it mean to prove a mathematical theorem and how does one know whether a mathematical proof is correct? Philosophers of mathematics also aim to clarify the relationships between mathematics and logic, human capabilities such as intuition, and the material universe.
Philosophy of physics
Philosophy of physics is the study of the fundamental, philosophical questions underlying modern physics, the study of matter and energy and how they interact. The main questions concern the nature of space and time, atoms and atomism. Also included are the predictions of cosmology, the results of the interpretation of quantum mechanics, the foundations of statistical mechanics, causality, determinism, and the nature of physical laws. Classically, several of these questions were studied as part of metaphysics (for example, those about causality, determinism, and space and time).
Philosophy of chemistry
Philosophy of chemistry is the philosophical study of the methodology and content of the science of chemistry. It is explored by philosophers, chemists, and philosopher-chemist teams. It includes research on general philosophy of science issues as applied to chemistry. For example, can all chemical phenomena be explained by quantum mechanics or is it not possible to reduce chemistry to physics? For another example, chemists have discussed the philosophy of how theories are confirmed in the context of confirming reaction mechanisms. Determining reaction mechanisms is difficult because they cannot be observed directly. Chemists can use a number of indirect measures as evidence to rule out certain mechanisms, but they are often unsure if the remaining mechanism is correct because there are many other possible mechanisms that they have not tested or even thought of. Philosophers have also sought to clarify the meaning of chemical concepts which do not refer to specific physical entities, such as chemical bonds.
Philosophy of biology
Philosophy of biology deals with epistemological, metaphysical, and ethical issues in the biological and biomedical sciences. Although philosophers of science and philosophers generally have long been interested in biology (e.g., Aristotle, Descartes, Leibniz and even Kant), philosophy of biology only emerged as an independent field of philosophy in the 1960s and 1970s. Philosophers of science began to pay increasing attention to developments in biology, from the rise of the Modern synthesis in the 1930s and 1940s to the discovery of the structure of Deoxyribonucleic acid (DNA) in 1953 to more recent advances in genetic engineering. Other key ideas such as the reduction of all life processes to biochemical reactions as well as the incorporation of psychology into a broader neuroscience are also addressed. Research in current philosophy of biology includes investigation of the foundations of evolutionary theory, and the role of viruses as persistent symbionts in host genomes. As a consequence the evolution of genetic content order is seen as the result of competent genome editors in contrast to former narratives in which error replication events (mutations) dominated.
Philosophy of medicine
Beyond medical ethics and bioethics, the philosophy of medicine is a branch of philosophy that includes the epistemology and ontology/metaphysics of medicine. Within the epistemology of medicine, evidence-based medicine (EBM) (or evidence-based practice (EBP)) has attracted attention, most notably the roles of randomisation, blinding and placebo controls. Related to these areas of investigation, ontologies of specific interest to the philosophy of medicine include Cartesian dualism, the monogenetic conception of disease and the conceptualization of 'placebos' and 'placebo effects'. There is also a growing interest in the metaphysics of medicine, particularly the idea of causation. Philosophers of medicine might not only be interested in how medical knowledge is generated, but also in the nature of such phenomena. Causation is of interest because the purpose of much medical research is to establish causal relationships, e.g. what causes disease, or what causes people to get better.
Philosophy of psychology
Philosophy of psychology refers to issues at the theoretical foundations of modern psychology. Some of these issues are epistemological concerns about the methodology of psychological investigation. For example, is the best method for studying psychology to focus only on the response of behavior to external stimuli or should psychologists focus on mental perception and thought processes? If the latter, an important question is how the internal experiences of others can be measured. Self-reports of feelings and beliefs may not be reliable because, even in cases in which there is no apparent incentive for subjects to intentionally deceive in their answers, self-deception or selective memory may affect their responses. Then even in the case of accurate self-reports, how can responses be compared across individuals? Even if two individuals respond with the same answer on a Likert scale, they may be experiencing very different things.
Other issues in philosophy of psychology are philosophical questions about the nature of mind, brain, and cognition, and are perhaps more commonly thought of as part of cognitive science, or philosophy of mind. For example, are humans rational creatures? Is there any sense in which they have free will, and how does that relate to the experience of making choices? Philosophy of psychology also closely monitors contemporary work conducted in cognitive neuroscience, evolutionary psychology, and artificial intelligence, questioning what they can and cannot explain in psychology.
Philosophy of psychology is a relatively young field, because psychology only became a discipline of its own in the late 1800s. In particular, neurophilosophy has just recently become its own field with the works of Paul Churchland and Patricia Churchland. Philosophy of mind, by contrast, has been a well-established discipline since before psychology was a field of study at all. It is concerned with questions about the very nature of mind, the qualities of experience, and particular issues like the debate between dualism and monism. Another related field is philosophy of language.
Philosophy of economics
Philosophy of economics is the branch of philosophy which studies philosophical issues relating to economics. It can also be defined as the branch of economics which studies its own foundations and morality. It can be categorized into three central topics. The first concerns the definition and scope of economics and by what methods it should be studied and whether these methods rise to the level of epistemic reliability associated with the other special sciences. For example, is it possible to research economics in such a way that it is value-free, establishing facts that are independent of the normative views of the researcher? The second topic is the meaning and implications of rationality. For example, can buying lottery tickets (increasing the riskiness of your income) at the same time as buying insurance (decreasing the riskiness of your income) be rational? The third topic is the normative evaluation of economic policies and outcomes. What criteria should be used to determine whether a given public policy is beneficial for society?
The philosophy of social science is the study of the logic and method of the social sciences, such as sociology, anthropology, and political science. Philosophers of social science are concerned with the differences and similarities between the social and the natural sciences, causal relationships between social phenomena, the possible existence of social laws, and the ontological significance of structure and agency.
The French philosopher, Auguste Comte (1798–1857), established the epistemological perspective of positivism in The Course in Positivist Philosophy, a series of texts published between 1830 and 1842. The first three volumes of the Course dealt chiefly with the physical sciences already in existence (mathematics, astronomy, physics, chemistry, biology), whereas the latter two emphasised the inevitable coming of social science: "sociologie". For Comte, the physical sciences had necessarily to arrive first, before humanity could adequately channel its efforts into the most challenging and complex "Queen science" of human society itself. Comte offers an evolutionary system proposing that society undergoes three phases in its quest for the truth according to a general 'law of three stages'. These are (1) the theological, (2) the metaphysical, and (3) the positive.
Comte's positivism established the initial philosophical foundations for formal sociology and social research. Durkheim, Marx, and Weber are more typically cited as the fathers of contemporary social science. In psychology, a positivistic approach has historically been favoured in behaviourism. Positivism has also been espoused by 'technocrats' who believe in the inevitability of social progress through science and technology.
The positivist perspective has been associated with 'scientism'; the view that the methods of the natural sciences may be applied to all areas of investigation, be it philosophical, social scientific, or otherwise. Among most social scientists and historians, orthodox positivism has long since lost popular support. Today, practitioners of both social and physical sciences instead take into account the distorting effect of observer bias and structural limitations. This scepticism has been facilitated by a general weakening of deductivist accounts of science by philosophers such as Thomas Kuhn, and new philosophical movements such as critical realism and neopragmatism. The philosopher-sociologist Jürgen Habermas has critiqued pure instrumental rationality as meaning that scientific-thinking becomes something akin to ideology itself.
- Encyclopaedia Britannica: Thomas S. Kuhn. "Instead, he argued that the paradigm determines the kinds of experiments scientists perform, the types of questions they ask, and the problems they consider important."
- Thornton, Stephen (2006). "Karl Popper". Stanford Encyclopedia of Philosophy. Retrieved 2007-12-01.
- Laudan, Larry (1983). "The Demise of the Demarcation Problem". In Adolf Grünbaum, Robert Sonné Cohen, Larry Laudan. Physics, Philosophy, and Psychoanalysis: Essays in Honor of Adolf Grünbaum. Springer. ISBN 90-277-1533-5.
- Uebel, Thomas (2006). "Vienna Circle". Stanford Encyclopedia of Philosophy. Retrieved 2007-12-01.
- Popper, Karl (2004). The logic of scientific discovery (reprint ed.). London & New York: Routledge Classics. ISBN 0-415-27844-9 First published 1959 by Hutchinson & Co.
- "Pseudoscientific – pretending to be scientific, falsely represented as being scientific", from the Oxford American Dictionary, published by the Oxford English Dictionary; Hansson, Sven Ove (1996)."Defining Pseudoscience", Philosophia Naturalis, 33: 169–176, as cited in "Science and Pseudo-science" (2008) in Stanford Encyclopedia of Philosophy. The Stanford article states: "Many writers on pseudoscience have emphasized that pseudoscience is non-science posing as science. The foremost modern classic on the subject (Gardner 1957) bears the title Fads and Fallacies in the Name of Science. According to Brian Baigrie (1988, 438), "[w]hat is objectionable about these beliefs is that they masquerade as genuinely scientific ones." These and many other authors assume that to be pseudoscientific, an activity or a teaching has to satisfy the following two criteria (Hansson 1996): (1) it is not scientific, and (2) its major proponents try to create the impression that it is scientific".
- For example, Hewitt et al. Conceptual Physical Science Addison Wesley; 3 edition (July 18, 2003) ISBN 0-321-05173-4, Bennett et al. The Cosmic Perspective 3e Addison Wesley; 3 edition (July 25, 2003) ISBN 0-8053-8738-2; See also, e.g., Gauch HG Jr. Scientific Method in Practice (2003).
- A 2006 National Science Foundation report on Science and engineering indicators quoted Michael Shermer's (1997) definition of pseudoscience: '"claims presented so that they appear [to be] scientific even though they lack supporting evidence and plausibility"(p. 33). In contrast, science is "a set of methods designed to describe and interpret observed and inferred phenomena, past or present, and aimed at building a testable body of knowledge open to rejection or confirmation"(p. 17)'.Shermer M. (1997). Why People Believe Weird Things: Pseudoscience, Superstition, and Other Confusions of Our Time. New York: W. H. Freeman and Company. ISBN 0-7167-3090-1. as cited by National Science Foundation; Division of Science Resources Statistics (2006). "Science and Technology: Public Attitudes and Understanding". Science and engineering indicators 2006.
- "A pretended or spurious science; a collection of related beliefs about the world mistakenly regarded as being based on scientific method or as having the status that scientific truths now have," from the Oxford English Dictionary, second edition 1989.
- Cargo Cult Science by Feynman, Richard. Retrieved 2011-07-21.
- Hempel, Carl G.; Paul Oppenheim (1948). "Studies in the Logic of Explanation". Philosophy of Science 15 (2): 135–175. doi:10.1086/286983.
- Salmon, Merrilee; John Earman, Clark Glymour, James G. Lenno, Peter Machamer, J.E. McGuire, John D. Norton, Wesley C. Salmon, Kenneth F. Schaffner (1992). Introduction to the Philosophy of Science. Prentice-Hall. ISBN 0-13-663345-5.
- Salmon, Wesley (1971). Statistical Explanation and Statistical Relevance. Pittsburgh: University of Pittsburgh Press.
- Woodward, James (2003). "Scientific Explanation". Stanford Encyclopedia of Philosophy. Retrieved 2007-12-07.
- Vickers, John (2013). "The Problem of Induction". Stanford Encyclopedia of Philosophy. Retrieved 2014-02-25.
- Baker, Alan (2013). "Simplicity". Stanford Encyclopedia of Philosophy. Retrieved 2014-02-25.
- Bogen, Jim (2013). "Theory and Observation in Science". Stanford Encyclopedia of Philosophy. Retrieved 2014-02-25.
- Levin, Michael (1984). "What Kind of Explanation is Truth?". In Jarrett Leplin. Scientific Realism. Berkeley: University of California Press. pp. 124–1139. ISBN 0-520-05155-6.
- Boyd, Richard (2002). "Scientific Realism". Stanford Encyclopedia of Philosophy. Retrieved 2007-12-01.
- Specific examples include:
- Popper, Karl (2002). Conjectures and Refutations. London & New York: Routledge Classics. ISBN 0-415-28594-1 First published 1963 by Routledge and Kegan Paul
- Smart, J. J. C. (1968). Between Science and Philosophy. New York: Random House.
- Putnam, Hilary (1975). Mathematics, Matter and Method (Philosophical Papers, Vol. I). London: Cambridge University Press.
- Putnam, Hilary (1978). Meaning and the Moral Sciences. London: Routledge and Kegan Paul.
- Boyd, Richard (1984). "The Current Status of Scientific Realism". In Jarrett Leplin. Scientific Realism. Berkeley: University of California Press. pp. 41–82. ISBN 0-520-05155-6.
- Stanford, P. Kyle (2006). Exceeding Our Grasp: Science, History, and the Problem of Unconceived Alternatives. Oxford University Press. ISBN 978-0-19-517408-3.
- Laudan, Larry (1981). "A Confutation of Convergent Realism". Philosophy of Science 48: 218–249. doi:10.1086/288975.
- van Fraassen, Bas (1980). The Scientific Image. Oxford: The Clarendon Press. ISBN 0-19-824424-X.
- Winsberg, Eric (September 2006). "Models of Success Versus the Success of Models: Reliability without Truth". Synthese 152: 1–19. doi:10.1007/s11229-004-5404-6.
- Stanford, P. Kyle (June 2000). "An Antirealist Explanation of the Success of Science". Philosophy of Science 67 (2): 266–284. doi:10.1086/392775.
- Longino, Helen (2013). "The Social Dimensions of Scientific Knowledge". Stanford Encyclopedia of Philosophy. Retrieved 2014-03-06.
- Aristotle, "Prior Analytics", Hugh Tredennick (trans.), pp. 181–531 in Aristotle, Volume 1, Loeb Classical Library, William Heinemann, London, UK, 1938.
- Ibn al-Haytham, Kitab al-manazir (Book of Optics), I-III and IV-V, ed. A. I. Sabra (Kuwait, 1983 and 2002); English translation of Books I-III on direct vision, 2 vols., trans. A. I. Sabra (London: Warburg Institute, 1989).
- Ibn al-Haytham: The First Scientist
- Clegg, Brian. “The First Scientist: A Life of Roger Bacon”. Carroll and Graf Publishers, NY, 2003, p. 2.
- Bacon, Francis Novum Organum (The New Organon), 1620. Bacon's work described many of the accepted principles, underscoring the importance of empirical results, data gathering and experiment. Encyclopædia Britannica (1911), "Bacon, Francis" states: [In Novum Organum, we ] "proceed to apply what is perhaps the most valuable part of the Baconian method, the process of exclusion or rejection. This elimination of the non-essential, ..., is the most important of Bacon's contributions to the logic of induction, and that in which, as he repeatedly says, his method differs from all previous philosophies."
- "John Stuart Mill (Stanford Encyclopedia of Philosophy)". plato.stanford.edu. Retrieved 2009-07-31.
- Michael Friedman, Reconsidering Logical Positivism (New York: Cambridge University Press, 1999), p xiv.
- See "Vienna Circle" in Stanford Encyclopedia of Philosophy.
- Smith, L.D. (1986). Behaviorism and Logical Positivism: A Reassessment of the Alliance. Stanford University Press. p. 314. ISBN 9780804713016. LCCN 85030366.
The secondary and historical literature on logical positivism affords substantial grounds for concluding that logical positivism failed to solve many of the central problems it generated for itself. Prominent among the unsolved problems was the failure to find an acceptable statement of the verifiability (later confirmability) criterion of meaningfulness. Until a competing tradition emerged (about the late 1950's), the problems of logical positivism continued to be attacked from within that tradition. But as the new tradition in the philosophy of science began to demonstrate its effectiveness—by dissolving and rephrasing old problems as well as by generating new ones—philosophers began to shift allegiances to the new tradition, even though that tradition has yet to receive a canonical formulation.
- Bunge, M.A. (1996). Finding Philosophy in Social Science. Yale University Press. p. 317. ISBN 9780300066067. LCCN lc96004399.
To conclude, logical positivism was progressive compared with the classical positivism of Ptolemy, Hume, d'Alembert, Compte, John Stuart Mill, and Ernst Mach. It was even more so by comparison with its contemporary rivals—neo-Thomisism, neo-Kantianism, intuitionism, dialectical materialism, phenomenology, and existentialism. However, neo-positivism failed dismally to give a faithful account of science, whether natural or social. It failed because it remained anchored to sense-data and to a phenomenalist metaphysics, overrated the power of induction and underrated that of hypothesis, and denounced realism and materialism as metaphysical nonsense. Although it has never been practiced consistently in the advanced natural sciences and has been criticized by many philosophers, notably Popper (1959 , 1963), logical positivism remains the tacit philosophy of many scientists. Regrettably, the anti-positivism fashionable in the metatheory of social science is often nothing but an excuse for sloppiness and wild speculation.
- "Popper, Falsifiability, and the Failure of Positivism". 7 August 2000. Retrieved 30 June 2012.
The upshot is that the positivists seem caught between insisting on the V.C. [Verifiability Criterion]—but for no defensible reason—or admitting that the V.C. requires a background language, etc., which opens the door to relativism, etc. In light of this dilemma, many folk—especially following Popper's "last-ditch" effort to "save" empiricism/positivism/realism with the falsifiability criterion—have agreed that positivism is a dead-end.
- Friedman, Reconsidering Logical Positivism (Cambridge U P, 1999), p xii.
- T. S. Kuhn, The Structure of Scientific Revolutions, 2nd. ed., Chicago: Univ. of Chicago Pr., 1970, p. 206. ISBN 0-226-45804-0
- Gauch 2002, p. 154, "Expressed as a single grand statement, science presupposes that the physical world is orderly and comprehensible. The most obvious components of this comprehensive presupposition are that the physical world exists and that our sense perceptions are generally reliable."
- Gould 1987, p. 120, “You cannot go to a rocky outcrop and observe either the constancy of nature's laws or the working of known processes. It works the other way around." You first assume these propositions and "then you go to the outcrop of rock.”
- Simpson 1963, pp. 24–48, "Uniformity is an unprovable postulate justified, or indeed required, on two grounds. First, nothing in our incomplete but extensive knowledge of history disagrees with it. Second, only with this postulate is a rational interpretation of history possible and we are justified in seeking—as scientists we must seek—such a rational interpretation."
- Paul Feyerabend, Against Method: Outline of an Anarchistic Theory of Knowledge (1975), ISBN 0-391-00381-X, ISBN 0-86091-222-1, ISBN 0-86091-481-X, ISBN 0-86091-646-4, ISBN 0-86091-934-X, ISBN 0-902308-91-2
- Paul Feyerabend entry by John Preston in the Stanford Encyclopedia of Philosophy, 2007-02-15
- Kuhn, T. S. (1970). "[Postscript]". The Structure of Scientific Revolutions, 2nd. ed. [Univ. of Chicago Pr]. ISBN 0-226-45804-0.
- Quine, Willard Van Orman (1980). "Two Dogmas of Empiricism". From a Logical Point of View. Harvard University Press. ISBN 0-674-32351-3.
- Gutting, Gary (2004), Continental Philosophy of Science, Blackwell Publishers, Cambridge, MA.
- Cat, Jordi (2013). "The Unity of Science". Stanford Encyclopedia of Philosophy. Retrieved 2014-03-01.
- Kitcher, P. Science, Truth, and Democracy, Oxford: Oxford University Press, 2001
- Weisberg, Michael; Needham, Paul; Hendry, Robin (2011). "Philosophy of Chemistry". Stanford Encyclopedia of Philosophy. Retrieved 2014-02-14.
- Hull D. (1969), What philosophy of biology is not, Journal of the History of Biology, 2, p. 241–268.
- Recent examples include Okasha S. (2006), Evolution and the Levels of Selection. Oxford: Oxford University Press, and Godfrey-Smith P. (2009), Darwinian Populations and Natural Selection. Oxford: Oxford University Press.
- Witzany G. (2010). "Biocommunication and Natural Genome Editing". Dortrecht: Springer Sciences and Business Media.
- Papineau, D., 1994. The Virtues of Randomization. British Journal for the Philosophy of Science, 45(2), pp.437 -450.
- Jstor, Worrall, J., 2002. What Evidence in Evidence-Based Medicine? Philosophy of Science, 69(3), p.S316-S330.
- Worrall, J., 2007. Why there's no cause to randomize. British Journal for the Philosophy of Science, 58, pp.451-488.
- Lee, K., 2012. The Philosophical Foundations of Modern Medicine, London/New York, Palgrave/Macmillan.
- Grünbaum, A., 1981. The Placebo Concept. Behavioural Research & Therapy, 19(2), pp.157-167.
- Gøtzsche, P.C., 1994. Is there logic in the placebo? Lancet, 344(8927), pp.925-926.
- Nunn, R., 2009. It's time to put the placebo out of our misery. British Medical Journal, 338, b1568.
- Springer Turner, A., 2012. "Placebos" and the logic of placebo comparison. Biology & Philosophy, 27(3), pp.419-432.
- PubMed, Worrall, J., 2011. Causality in medicine: Getting back to the Hill top. Preventive Medicine, 53(4-5), pp.235-238.
- Springer, Cartwright, N., 2009. What are randomised controlled trials good for? Philosophical Studies, 147(1), pp.59-70.
- Mason, Kelby; Sripada, Chandra Sekhar; Stich, Stephen (2010). "Philosophy of Psychology" (PDF). In Moral, Dermot. Routledge Companion to Twentieth-Century Philosophy. London: Routledge.
- Hausman, Daniel (Dec 18, 2012). "Philosophy of Economics". Stanford Encyclopedia of Philosophy. Stanford University. Retrieved 20 February 2014.
- Stanford Encyclopaedia: Auguste Comte
- Giddens, Positivism and Sociology, 1
- Schunk, Learning Theories: An Educational Perspective, 5th, 315
- Outhwaite, William, 1988 Habermas: Key Contemporary Thinkers, Polity Press (Second Edition 2009), ISBN 978-0-7456-4328-1 p.68
- Gauch, Hugh G. (2002). Scientific Method in Practice. Cambridge University Press.
- Kneale, William; Martha Kneale (1962). The Development of Logic. London: Oxford University Press. p. 243. ISBN 0-19-824183-6. ISBN.
- Simpson, G. G. (1963). "Historical science". In Albritton, Jr., C. C. Fabric of geology. Stanford, California: Freeman, Cooper, and Company. pp. 24–48.
- Gould, Stephen J (1987). Time's Arrow, Time's Cycle: Myth and Metaphor in the Discovery of Geological Time. Cambridge, MA: Harvard University Press. p. 120. ISBN 0674891996.
- Whitehead, A.N. (1997) . Science and the Modern World. Lowell Lectures. Free Press. p. 135. ISBN 978-0-684-83639-3. LCCN 67002244.
- Bovens, L. and Hartmann, S. (2003), Bayesian Epistemology, Oxford University Press, Oxford.
- Gutting, Gary (2004), Continental Philosophy of Science, Blackwell Publishers, Cambridge, MA.
- Kuhn, T. S. (1970). The Structure of Scientific Revolutions, 2nd. ed. [Univ. of Chicago Pr]. ISBN 0-226-45804-0.
- Losee, J. (1998), A Historical Introduction to the Philosophy of Science, Oxford University Press, Oxford, UK.
- Papineau, David (2005) Science, problems of the philosophy of. Oxford Companion to Philosophy. Oxford.
- Salmon, Merrilee; John Earman, Clark Glymour, James G. Lenno, Peter Machamer, J.E. McGuire, John D. Norton, Wesley C. Salmon, Kenneth F. Schaffner (1992). Introduction to the Philosophy of Science. Prentice-Hall. ISBN 0-13-663345-5.
- Popper, Karl, (1963) Conjectures and Refutations: The Growth of Scientific Knowledge, ISBN 0-415-04318-2
- van Fraassen, Bas (1980). The Scientific Image. Oxford: The Clarendon Press. ISBN 0-19-824424-X.
- Shaw, Jeffrey M. (2014) Illusions of Freedom: Thomas Merton and Jacques Ellul on Technology and the Human Condition. Eugene, OR: Wipf and Stock. ISBN 978-1625640581.
- Ziman, John (2000). Real Science: what it is, and what it means. Cambridge, Uk: Cambridge University Press.
- Philosophy of science at PhilPapers
- Philosophy of science at the Indiana Philosophy Ontology Project
- Philosophy of science entry in the Internet Encyclopedia of Philosophy
- An introduction to the Philosophy of Science, aimed at beginners - Paul Newall.
- Essays on concepts in the Philosophy of Science at The Galilean Library.