bluuebunny/crossref_metadata_2025 huggingface dataset:
Colour, theories of
Authors: Hilbert David R.
Published: September 2018

The world as perceived by human beings is full of colour. The world as described by physical scientists is composed of colourless particles and fields. Philosophical theories of colour since the Scientific Revolution have been driven primarily by a desire to harmonize these two apparently conflicting pictures of the world. Any adequate theory of colour has to be consistent with the characteristics of colour as perceived without contradicting the deliverances of the physical sciences.

Given this conception of the aim of a theory of colour, there are three possibilities for resolving the apparent conflict between the scientific and perceptual facts. The first is to deny that physical objects have colours. Theories of this kind admit that objects appear coloured but maintain that these appearances are misleading. The conflict is resolved by removing colour from the external world. Second, it might be that colour is a relational property. For an object to possess a particular colour it must be related in the right way to a perceiver. One common version of this view analyses colour as a disposition to cause particular kinds of perceptual experience in a human being. Since the physical sciences deal only with the intrinsic properties of physical objects and their relations to other physical objects and not their relations to perceiving subjects, the possibility of conflict is removed. A third possible response is to maintain that colour really is a property of external objects and that the conflict is merely apparent. Some theories of this form maintain that colour is identical to a physical property of objects. Others maintain that colour is a property that physical objects possess over and above all their physical properties. Philosophical discussions of colour typically take the form of either elaborating on one of these three possibilities or attempting to show more generally that one of these three types of response is to be preferred to the others.
Computer science
Authors: Winnie John
Published: September 2018

At first sight, computers would seem to be of minimal philosophical importance; mere symbol manipulators that do the sort of things that we can do anyway, only faster and more conveniently. Nevertheless, computers are being used to illuminate the cognitive abilities of the human and animal mind, explore the organizational principles of life, and open up new approaches to modelling nature. Furthermore, the study of computation has changed our conception of the limits and methodology of scientific knowledge.

Computers have been able to do all this for two reasons. The first is that material computing power (accuracy, storage and speed) permits the development and exploration of models of physical (and mental) systems that combine structural complexity with mathematical intransigence. Through simulation, computational power allows exploration where mathematical analysis falters. The second reason is that a computer is not merely a concrete device, but also can be studied as an abstract object whose rules of operation can be specified with mathematical precision; consequently, its strengths and limitations can be systematically investigated, exploited and appreciated. Herein lies that area of computer science of most interest to philosophers: the theory of computation and algorithms. It is here where we have learned what computers can and cannot do in principle.
Conservation principles
Authors: Cushing James T.
Published: September 2018

In antiquity ‘self-evident’ principles were used to argue for the conservation of certain quantities. The concept of quantitative conservation laws, such as those of mass and energy, is of much later origin. Even prior to the development of modern mechanics, symmetries were employed to solve some dynamical problems. The relation between conserved quantities and symmetries has come to play a central role in the physical sciences. Conservation laws may reflect as much about the way the human mind organizes the phenomena of the world as they do about physical reality itself.
Conventionalism
Authors: Horwich Paul
Published: September 2018

How is it known that every number has a successor, that straight lines can intersect each other no more than once, that causes precede their events, and that the electron either went through the slit or it did not? In cases like these it is not easy to find observable evidence, and it is implausible to postulate special modes of intuitive access to the phenomena in question. Yet such theses are relied on in scientific discourse and can hardly be dismissed as meaningless metaphysical excess. In response to this problem the positivists and empiricists (notably Poincaré, Hilbert, Carnap, Reichenbach and Ayer) developed a strategy known as conventionalism. The idea was that certain statements, including fundamental principles of logic, arithmetic and geometry, are asserted as a matter of conventional stipulation, being no more than definitions of some of their constituent terms; consequently they must be true, our commitment to them cannot but be justified, and the facts in virtue of which they are true are simply the facts of our having made those particular decisions about the use of words. This doctrine was a compelling and powerful weapon in the positivist–empiricist arsenal, evolving throughout the 1920s, 1930s and 1940s. But it fell into disfavour under a barrage of serious challenges due mainly to Quine. How are ‘conventions’ to be identified as such? How could they possibly provide words with meanings, or have the epistemological import that is claimed for them? How could arbitrary, contingent decisions about the use of words result in the existence of necessary facts? In the absence of satisfactory replies to these objections few philosophers these days believe that conventionalism can settle the semantic, epistemological and metaphysical questions that it was intended to answer. However, certain aspects of the view remain defensible and interesting.
Cosmology
Authors: McMullin Ernan
Published: September 2018

The term ’cosmology’ has three main uses. At its most general, it designates a worldview, for example, the Mayan cosmology. In the early eighteenth century, shortly after the term made its first appearance, Christian Wolff used it to draw a distinction between physics, the empirical study of the material world, and cosmology, the branch of metaphysics dealing with material nature in its most general aspects. This usage remained popular into the twentieth century, especially among Kantian and neo-scholastic philosophers. But recent developments in science that allow the construction of plausible universe models have, effectively, pre-empted the use of the term in order to designate the science that deals with the origins and structure of the physical universe as a whole.

Cosmology may be said to have gone through three major phases, each associated with a single major figure – Aristotle, Newton and Einstein. The ancient Greeks were the first to attempt to give a reasoned account of the cosmos. Aristotle constructed a complex interlocking set of spheres centred on an immovable central earth to account for the motions of the heavenly bodies. Newton formulated a theory of gravitational force that required space and time to be both absolute and infinite. Though the laws of nature could, in principle, be specified, nothing could be said about the origins or overall structure of the cosmos. In 1915, Einstein proposed a general theory of relativity whose field-equations could be satisfied by numerous universe-models. Hubble’s discovery of the galactic red shift in 1929 led Lemaître in 1931 to choose from among these alternatives an expanding-universe model, which, though challenged in the 1950s by a rival steady-state theory, became the ‘standard’ view after the cosmic microwave background radiation it had predicted was observed in 1964. The ‘Big Bang’ theory has since been modified in one important respect by the addition of an inflationary episode in the first fraction of a second of cosmic expansion. As a ‘cosmic’ theory, it continues to raise issues of special interest to philosophers.
Crucial experiments
Authors: Achinstein Peter
Published: September 2018

A ‘crucial experiment’ allegedly establishes the truth of one of a set of competing theories. Francis Bacon (1620) held that such experiments are frequent in the empirical sciences and are particularly important for terminating an investigation. These claims were denied by Pierre Duhem (1905), who maintained that crucial experiments are impossible in the physical sciences because they require a complete enumeration of all possible theories to explain a phenomenon – something that cannot be achieved. Despite Duhem, scientists frequently regard certain experiments as crucial in the sense that the experimental result helps make one theory among a set of competitors very probable and the others very improbable, given what is currently known.
Darwin, Charles Robert (1809–82)
Authors: Bowler Peter J.
Published: September 2018

Darwin’s On the Origin of Species (1859) popularized the theory that all living things have evolved by natural processes from pre-existing forms. This displaced the traditional belief that species were designed by a wise and benevolent God. Darwin showed how many biological phenomena could be explained on the assumption that related species are descended from a common ancestor. Furthermore, he proposed a radical mechanism to explain how the transformations came about, namely, natural selection. This harsh and apparently purposeless mechanism was seen as a major threat to the claim that the universe has a transcendent goal.

Because Darwin openly extended his evolutionism to include the human race, it was necessary to re-examine the foundations of psychology, ethics and social theory. Moral values might be merely the rationalization of instinctive behaviour patterns. Since the process which produced these patterns was driven by struggle, it could be argued that society must inevitably reflect the harshness of nature (’social Darwinism’). Darwin’s book has been seen as the trigger for a ’scientific revolution’. It took many decades for both science and Western culture to assimilate the more radical aspects of Darwin’s theory. But since the mid-twentieth century Darwin’s selection mechanism has become the basis for a highly successful theory of evolution, the human consequences of which are still being debated.
Decision and game theory
Authors: Bicchieri Cristina
Published: September 2018

Decision theory studies individual decision-making in situations in which an individual’s choice neither affects nor is affected by other individuals’ choices; while game theory studies decision-making in situations where individuals’ choices do affect each other. Decision theory asks questions like: what does it mean to choose rationally? How should we make choices when the consequences of our actions are uncertain? Buying insurance and deciding which job to take are examples of the kind of decisions studied by this discipline. Game theory instead applies to all decisions that have a strategic component. The choices of an oligopolist, voting strategies, military tactical problems, deterrence, but also common phenomena such as threatening, promising, conflict and cooperation are its subject matter. In a strategic situation, the goal is not just to choose rationally, but to choose in such a way that a mutual solution is achieved, so that choices ‘coordinate’ in the right way. The formal methods developed by game theory do not require that the subject making a choice be an intentional agent: coordinated interaction between animals or computers can be successfully modelled as well.
Demarcation problem
Authors: Achinstein Peter
Published: September 2018

The problem of demarcation is to distinguish science from nonscientific disciplines that also purport to make true claims about the world. Various criteria have been proposed by philosophers of science, including that science, unlike ‘non-science’, (1) is empirical, (2) seeks certainty, (3) proceeds by the use of a scientific method, (4) describes the observable world, not an unobservable one, and (5) is cumulative and progressive.

Philosophers of science offer conflicting viewpoints concerning these criteria. Some reject one or more completely. For example, while many accept the idea that science is empirical, rationalists reject it, at least for fundamental principles regarding space, matter and motion. Even among empiricists differences emerge, for example between those who advocate that scientific principles must be verifiable and those who deny that this is possible, claiming that falsifiability is all that is required.

Some version of each of these five criteria – considered as goals to be achieved – may be defensible.
Determinism and indeterminism
Authors: Butterfield Jeremy
Published: September 2018

Over the centuries, the doctrine of determinism has been understood, and assessed, in different ways. Since the seventeenth century, it has been commonly understood as the doctrine that every event has a cause; or as the predictability, in principle, of the entire future. To assess the truth of determinism, so understood, philosophers have often looked to physical science; they have assumed that their current best physical theory is their best guide to the truth of determinism. It seems that most have believed that classical physics, especially Newton’s physics, is deterministic. And in this century, most have believed that quantum theory is indeterministic. Since quantum theory has superseded classical physics, philosophers have typically come to the tentative conclusion that determinism is false.

In fact, these impressions are badly misleading. The above formulations of determinism are unsatisfactory. Once we use a better formulation, we see that there is a large gap between the determinism of a given physical theory, and the bolder, vague idea that motivated the traditional formulations: the idea that the world in itself is deterministic. Admittedly, one can make sense of this idea by adopting a sufficiently bold metaphysics; but it cannot be made sense of just by considering determinism for physical theories.

As regards physical theories, the traditional impression is again misleading. Which theories are deterministic turns out to be a subtle and complicated matter, with many open questions. But broadly speaking, it turns out that much of classical physics, even much of Newton’s physics, is indeterministic. Furthermore, the alleged indeterminism of quantum theory is very controversial: it enters, if at all, only in quantum theory’s account of measurement processes, an account which remains the most controversial part of the theory.
Discovery, logic of
Authors: Nickles Thomas
Published: September 2018

Bacon, Descartes, Newton and other makers of the Scientific Revolution claimed to have found and even used powerful logics or methods of discovery, step-by-step procedures for systematically generating new truths in mathematics and the natural sciences. Method of discovery was also the prime method of justification: generation by correct method was something akin to logical derivation and thus the strongest justification a claim could have. The ’logic’ of these methods was deductive, inductive or both. By the mid-nineteenth century, logic of discovery was yielding to the more flexible and theory-tolerant method of hypothesis as the ’official’ method of science. In the twentieth century, Karl Popper and most logical positivists completed the methodological reversal from generativism to consequentialism by setting their hypothetico-deductive method against logic of discovery. What is epistemologically important, they said, is not how new claims are generated but how they fare in empirical tests of their predictive consequences. They demoted discovery to the status of historical anecdote and psychological process. Since the late 1950s, however, there has been a revival of interest in methodology of discovery on two fronts – logical and historical. An earlier explosion of work in symbolic logic had led to automata theory, computers, and then artificial intelligence. Meanwhile, a maturing history of science was furnishing information on science as a process, on how historical actors and communities actually discovered or constructed their claims and practices. Now, in the 1980s and 1990s, liberal epistemologists once again admit discovery as a legitimate topic for philosophy of science. Yet attempts to both naturalize and to socialize inquiry pose new challenges to the possibility of logics of discovery. Its strong associations with ’the’ method of science makes logic of discovery a target of postmodernist attack, but a more flexible construal is defensible.
Einstein, Albert (1879–1955)
Authors: Fine Arthur , Howard Don , Norton John D.
Published: September 2018

Albert Einstein was a German-born Swiss and American naturalized physicist and the twentieth century’s most prominent scientist. He produced the special and general theories of relativity, which overturned the classical understanding of space, time and gravitation. According to the special theory (1905), uniformly moving observers with different velocities measure the same speed for light. From this he deduced that the length of a system shrinks and its clocks slow at speeds approaching that of light. The general theory (completed 1915) proceeds from Hermann Minkowski’s geometric formulation of special relativity as a four-dimensional spacetime. Einstein’s theory allows, however, that the geometry of spacetime may vary from place to place. This variable geometry or curvature is associated with the presence of gravitational fields. Acting through geometrical curvature, these fields can slow clocks and bend light rays.

Einstein made many fundamental contributions to statistical mechanics and quantum theory, including the demonstration of the atomic character of matter and the proposal that light energy is organized in spatially discrete light quanta. In later life, he searched for a unified theory of gravitation and electromagnetism as an alternative to the quantum theory developed in the 1920s. He complained resolutely that this new quantum theory was not complete. Einstein’s writings in philosophy of science developed a conventionalist position, stressing our freedom to construct theoretical concepts; his later writings emphasized his realist tendencies and the heuristic value of the search for mathematically simple laws.
Ecology
Authors: Beatty John
Published: September 2018

Philosophers of science have paid relatively little attention to ecology (compared to other areas of biology like evolution and genetics), but ecology poses many interesting foundational and methodological problems. For example, the problems of clarifying the differences and causal connections between the various levels of the ecological hierarchy (organism, population, community, ecosystem…); the issue of how central evolutionary biology is to ecology; long-standing issues concerning the extent to which the domain of ecology is more law-governed or more a matter of historical contingency, and the related question of whether ecologists should rely more on laboratory/manipulative versus field/comparative methods of investigation.
Explanation
Authors: Kitcher Philip
Published: September 2018

Philosophical reflections about explanation are common in the history of philosophy, and important proposals were made by Aristotle, Hume, Kant and Mill. But the subject came of age in the twentieth century with the provision of detailed models of scientific explanation, prominently the covering-law model, which takes explanations to be arguments in which a law of nature plays an essential role among the premises. In the heyday of logical empiricism, philosophers achieved a consensus on the covering law model, but, during the 1960s and 1970s, that consensus was challenged through the recognition of four major kinds of difficulty: first, a problem about the relation between idealized arguments and the actual practice of explaining; second, the difficulty of characterizing the underlying notion of a law of nature; third, troubles in accounting for the asymmetries of explanation; and, four, recalcitrant problems in treating statistical explanations.

Appreciation of these difficulties has led to the widespread abandonment of the covering-law model, and currently there is no consensus on how to understand explanation. The main contemporary view seeks to characterize explanation in terms of causation, that is, explanations are accounts that trace the causes of the events (states, conditions) explained. Other philosophers believe that there is no general account of explanation, and offer pragmatic theories. A third option sees explanation as consisting in the unification of the phenomena. All of these approaches have associated successes, and face particular anomalies.

Although the general character of explanation is now a subject for philosophical debate, some particular kinds of explanation seem to be relatively well understood. In particular, functional explanations in biology, which logical empiricists found puzzling, now appear to be treated quite naturally by supposing them to make tacit reference to natural selection.
Fictionalism
Authors: Fine Arthur
Published: September 2018

‘Fictionalism’ generally refers to a pragmatic, antirealist position in the debate over scientific realism. The use of a theory or concept can be reliable without the theory being true and without the entities mentioned actually existing. When truth (or existence) is lacking we are dealing with a fiction. Thus fictionalism is a corollary of instrumentalism, the view that what matters about a theory is its reliability in practice, adding to it the claim that science often employs useful fictions. Perhaps the fullest expression of fictionalism occurs in Vaihinger’s once popular philosophy of ‘as if’.
Field theory, classical
Authors: Wilson Mark
Published: September 2018

A physical quantity (such as mass, temperature or electrical strength) appears as a field if it is distributed continuously and variably throughout a region. In distinction to a ’lumped’ quantity, whose condition at any time can be specified by a finite list of numbers, a complete description of a field requires infinitely many bits of data (it is said to ’possess infinite degrees of freedom’). A field is classical if it fits consistently within the general framework of classical mechanics. By the start of the twentieth century, orthodox mechanics had evolved to a state of ontological dualism, incorporating a worldview where massive matter appears as ’lumped’ points which communicate electrical and magnetic influences to one another through a continuous intervening medium called the electromagnetic field. The problem of consistently describing how matter and fields function together has yet to be fully resolved.
French philosophy of science
Authors: Gutting Gary
Published: September 2018

A distinctively French tradition in the philosophy of science began with Descartes, continued through the Enlightenment in works such as D’Alembert’s Discours préliminaire and the Encyclopédie, and flowered in the ninteenth and the early twentieth century with the work of Comte, Duhem, Meyerson and Poincaré. Throughout the twentieth century, the dominant fashions in French philosophy derived more and more from German influences, especially idealism and phenomenology (Hegel to Heidegger). But amidst these developments, there persisted an essentially autonomous tradition of French philosophy of science that offered an indigenous alternative to the Germanic imports. Here the key figure was Gaston Bachelard (1884–1962), for many years professor at the Sorbonne and director of the Institut d’Histoire des Sciences et des Techniques. His work was continued and modified by Georges Canguilhem (1904–95), his successor at the Institute, who himself was an important influence on philosophers such as Louis Althusser, Michel Foucault and Michel Serres. Jean Cavaillès’ critique of Husserl’s philosophy of mathematics and his effort to develop a neo-Hegelian alternative to it had deep affinities with Bachelard’s work and was also an important influence on Canguilhem.

The most important general features of twentieth-century French philosophy of science appear if we contrast it with its two major rivals: existential phenomenology and logical positivism. Existential phenomenology is a ‘philosophy of the subject’, maintaining that ultimate truth resides in the immediacy of lived experience. Bachelard and his followers, by contrast, proposed a ‘philosophy of the concept’, for which experiential immediacy is subordinate to and corrected by concepts produced by rational reflection. This process of rational reflection is, moreover, embodied in science, which is not, as existential phenomenology maintains, a derivative and incomplete form of knowing, but the very paradigm of knowledge. In giving science a privileged epistemic position, the French philosophers of science are like the logical positivists. But, unlike the positivists, they treat science as essentially historical, irreducible in either method or content to the rigour of a formal system. They also opposed the positivists’ effort to find the foundations of scientific knowledge in sense experience, maintaining that there are no simply given data and that all experience is informed by conceptual interpretation.
Galilei, Galileo (1564–1642)
Authors: McMullin Ernan
Published: September 2018

Galileo Galilei, one of the most colourful figures in the long history of the natural sciences, is remembered best today for two quite different sorts of reason. He has often been described as the ’father’ of modern natural science because of his achievements in the fields of mechanics and astronomy, and for what today would be called his philosophy of science, his vision of how the practice of science should be carried on and what a completed piece of natural science should look like. While none of the elements of that philosophy was entirely new, the way in which he combined them was so effective that it did much to shape all that came after in the sciences. In the popular mind, however, as a continuing stream of biographies attest, it is his struggle with Church authority that remains the centre of attention, symbolic as it is of the often troubled, but always intriguing, relationship between science and religion.
Genetics
Authors: Darden Lindley
Published: September 2018

Genetics studies the problem of heredity, namely why offspring resemble their parents. The field emerged in 1900 with the rediscovery of the 1865 work of Gregor Mendel. William Bateson called the new field ‘genetics’ in 1905, and W. Johannsen used the term ‘gene’ in 1909. By analysing data about patterns of inheritance of characters, such as yellow and green peas, Mendelian geneticists infer the number and type of hypothetical genes. The major components of the theory of the gene, which proposed the model of genes as beads on a string, were in place by the 1920s. In the 1930s, the field of population genetics emerged from the synthesis of results from Mendelian genetics with Darwinian natural selection. Population geneticists study the distribution of genes in the gene pool of a population and changes caused by selection and other factors. The 1940s and 1950s saw the development of molecular genetics, which investigates problems about gene reproduction, mutation and function at the molecular level.

Philosophical issues arise: the question about the evidence for the reality of hypothetical genes, and the status of Mendel’s laws, given that they are not universal generalizations. Debates have occurred about the nature of the relation between Mendelian and molecular genetics. Population genetics provides the perspective of the gene as the unit of selection in evolutionary theory. Molecular genetics and its accompanying technologies raise ethical issues about humans’ genetic information, such as the issue of privacy of information about one’s genome and the morality of changing a person’s genes. The nature–nurture debate involves the issue of genetic determinism, the extent to which genes control human traits and behaviour.
Hanson, Norwood Russell (1924–67)
Authors: MacKinnon Edward
Published: September 2018

Hanson was a philosopher of science who introduced novel ways of relating logical, historical and linguistic analyses. His best-known book, Patterns of Discovery, stressed the theory-ladeness of observational reports and argued that causality is a feature of inference systems, rather than of nature as such. He pioneered in combining historical and analytic analyses of significant breakthroughs in science. Though he clarified patterns of discovery he never succeeded in the project of developing a logic of discovery, or an account of the inferences leading from problematic situations to novel explanatory hypotheses. A man of many talents, he also made contributions to the history of science, aerodynamics and epistemology.
Heideggerian philosophy of science
Authors: Rouse Joseph
Published: September 2018

Heidegger’s importance in the philosophy of science stems less from his scattered remarks about science than from the larger conception of intentionality and ontology that informs them. Heidegger’s earliest major work, Being and Time (1927), displayed everyday practical purposive activity as the most fundamental setting for the disclosure of things in the world. Heidegger claimed that the traditional epistemological conception of a subject who represents objects was derivative from and dependent upon such ongoing everyday practical engagement with one’s surroundings. Science was then supposed to be the practice that allows things to show themselves shorn of their significance within the ’in-order-to-for-the-sake-of’ structure of everyday activity; nevertheless, the sense of scientific claims remained dependent upon the everyday interactions from which they were abstracted.

Shortly after writing Being and Time, Heidegger revised his project in ways that also transformed his account of science. His overall project shifted from describing the transcendental structure of the meaning of being, to interpreting the ’history of being’. Science was reinterpreted as an activity (’research’) closely allied with machine technology, and oriented towards more extensive and intensive manipulation and ordering of things. Understood as such, science for Heidegger was an essential manifestation of the modern age. Whereas, earlier, he thought that science presupposed a philosophical ontology, he eventually portrayed science and technology as the conclusion of the philosophical tradition. While philosophical metaphysics and epistemology were thus naturalized, Heidegger was concerned with the possibility of a way of thinking outside this convergence of scientific and philosophical metaphysics.
Helmholtz, Hermann von (1821–94)
Authors: Chevalley Catherine
Published: September 2018

In physiology, physics, mathematics, aesthetic theory and epistemology, Helmholtz intervened, and innovated. He contributed to the physiology of perception through work on the central nervous system, followed by work on optics and acoustics. He invented instruments, such as the opthalmoscope and introduced the mathematical principle of the conservation of energy to physics. For geometry, Helmholtz elaborated on the concept of an n-dimensional manifold. He secured the influence of the ‘Berlin physics’, introduced Faraday and Maxwell to Germany, refined the theory of electrodynamics and reflected on the role of discrete entities in physics. Having become the most influential representative of German science and its uncontested spokesperson, he repeated the importance of the connection between education and research and the necessity not to separate the natural sciences (Naturwissenschaften) from the social sciences (Geisteswissenschaften). This monumental body of work is experiencing a revival of interest today as historians of both science and culture consider it in a new light. But the question remains of how to characterize what we might call ‘the Helmholtz effect’ in philosophy. Why was Helmholtz equally influential not only on Cassirer, Husserl, Schlick, Meyerson and Freud, but also on the principal founders of contemporary physics; Einstein, Bohr and Heisenberg? To grasp this, we must understand the constant interaction between science and philosophy which characterized, even permitted, the extraordinary developments in mathematics, physics and physiology in Germany at that time. Here the connection between Helmholtz and Kant is fundamental, since ‘the Helmholtz effect’ transformed the Kantian heritage. Helmholtz did not write a systematic philosophical work, but in redefining fundamental epistemological concepts and constructing a large part of the conceptual structure in which both philosophy and relativistic and quantum physics developed during the early twentieth century, he modified the very problems of epistemology.
Idealizations
Authors: Laymon Ronald
Published: September 2018

Scientific analyses of particular phenomena are invariably simplified or idealized. The universe does not contain only two bodies as assumed in Newton’s derivation of Kepler’s laws, or only one body as assumed in Schwarzschild’s relativistic update; real economic agents do not act exclusively to maximize expected utilities, the surfaces of ordinary plate condensers are not infinitely extended planes, and the sine of an angle is not equal in measure to the angle itself. There are many reasons for the use of such misdescriptions. First and foremost is the need to achieve mathematical tractability. Science gets nowhere unless numbers, or numerical constraints, are produced that can form the basis of predictions and explanations. Idealizations may also be required because of the unavailability of certain data or because of the absence of necessary auxiliary theories.

The philosophical problem is to make normative sense of this common but complex scientific practice. For example, how can theories be tested given that they connect to the world only through the intermediary of idealized descriptions? In what sense can there be scientific explanations if what is to be explained must be misdescribed before theory can be brought to bear? The fact that idealizations can often be improved, with corresponding salutary effect on the accuracy of prediction or usefulness of explanation, suggests that idealizations should be understood as part of some sort of convergent process.
Inductive inference
Authors: Maher Patrick
Published: September 2018

According to a long tradition, an inductive inference is an inference from a premise of the form ‘all observed A are B’ to a conclusion of the form ‘all A are B‘. Such inferences are not deductively valid, that is, even if the premise is true it is possible that the conclusion is false, since unobserved As may differ from observed ones. Nevertheless, it has been held that the premise can make it reasonable to believe the conclusion, even though it does not guarantee that the conclusion is true.

It is now generally allowed that there are many other patterns of inference that can also provide reasonable grounds for believing their conclusions, even though their premises do not guarantee the truth of their conclusions. In current usage, it is common to call all such inferences inductive. It has been widely thought that all knowledge of matters of fact that we have not observed must be based on inductive inferences from what we have observed. In particular, all knowledge of the future is, on this view, based on induction.
Information theory
Authors: Sayre Kenneth M.
Published: September 2018

Information theory was established in 1948 by Claude Shannon as a statistical analysis of factors pertaining to the transmission of messages through communication channels. Among basic concepts defined within the theory are information (the amount of uncertainty removed by the occurrence of an event), entropy (the average amount of information represented by events at the source of a channel), and equivocation (the ‘noise’ that impedes faithful transmission of a message through a channel). Information theory has proved essential to the development of space probes, high-speed computing machinery and modern communication systems.

The information studied by Shannon is sharply distinct from information in the sense of knowledge or of propositional content. It is also distinct from most uses of the term in the popular press (‘information retrieval’, ‘information processing’, ‘information highway’, and so on). While Shannon’s work has strongly influenced academic psychology and philosophy, its reception in these disciplines has been largely impressionistic. A major problem for contemporary philosophy is to relate the statistical conceptions of information theory to information in the semantic sense of knowledge and content.
Keynes, John Maynard (1883–1946)
Authors: Schabas Margaret
Published: September 2018

Keynes is best known as an economist but, in the tradition of John Stuart Mill and William Stanley Jevons, he also made significant contributions to inductive logic and the philosophy of science. Keynes’ only book explicitly on philosophy, A Treatise on Probability (1921), remains an important classic on the subject. It develops a non-frequentist interpretation of probability as the key to sound judgment and scientific reasoning. His General Theory of Employment, Interest and Money (1936) is the watershed of twentieth-century macroeconomics. While not, strictly speaking, a philosophical work, it nonetheless advances distinct readings of rationality, uncertainty and social justice.
Koyré, Alexandre (1892–1964)
Authors: Redondi Pietro
Published: September 2018

The scope of his research and his effort to give civilization meaning make Alexandre Koyré one of the boldest and most influential of twentieth-century historians of scientific thought. He was Russian of origin, German by philosophical training, French by adoption, and chose the USA as his second intellectual homeland. From the mysticism of the Renaissance to Romantic philosophy, from Copernican theory to Newtonian synthesis, he interpreted modern cosmology in the light of ‘the unity of human thought’ and of mathematical realism, as both effect and origin of a ‘spiritual’ revolution.
Kuhn, Thomas Samuel (1922–96)
Authors: Hoyningen-Huene Paul
Published: September 2018

The early 1960s saw substantial turmoil in the philosophy of science, then dominated by logical empiricism. Most important was the confrontation of the prevailing philosophical tradition with the history of science. Whereas the philosophy of science was mainly normatively oriented, that is it tried to delineate what good science should look like, historical studies seemed to indicate that the practice of science both past and present did not follow those prescriptions.

Thomas S. Kuhn was educated as a theoretical physicist but soon turned to the history and philosophy of science. In 1962, he published The Structure of Scientific Revolutions (SSR). This book was the single most important publication advancing the confrontation between the history and the philosophy of science; it is now a classic in science studies. SSR was most influential not only in the discussion within philosophy but also in various other fields, especially the social sciences. The central concepts of SSR, like scientific revolution, paradigm shift and incommensurability, have been in the focus of philosophical discussion for many years, and the term ‘paradigm’ has even become a household word (although mostly not in Kuhn’s intended sense). After SSR, Kuhn continued to develop his theory; apart from minor modifications it is mainly the explication of SSR’s more intricate philosophical topics, especially of incommensurability, which is characteristic of his later work.
Life, origin of
Authors: Moss Lenny
Published: September 2018

The appearance of maggots on meat or of intestinal tapeworms supported an ancient belief in the spontaneous generation of life. This idea was challenged in the seventeenth century but not abandoned before Pasteur’s experiments. Scientists now agree that terrestrial life had a single origin, but differ in explanations. Some believe that life began with the onset of protein-based metabolism, supported by evidence of spontaneous abiotic amino acid synthesis and theoretical models of self-sustaining and evolving systems of enzymes. Others believe life began with the appearance of nucleic acid-based molecular replicators and have organized their research efforts around the vision of a primordial ‘RNA world’.
Linnaeus, Carl von (1707–78)
Authors: Stevens P.F.
Published: September 2018

Linnaeus was educated in Sweden, and became a doctor of medicine in Harderwijk, Holland, in 1735. He visited other European countries then, but he never left Sweden after his return in 1738. After practising as a physician in Stockholm, he moved to Uppsala University as professor of medicine and botany in 1741. He articulated four different but complementary ways of understanding nature – through two kinds of classification, and through what can be called developmental and functional/ecological interactions. Linnaeus is best known for his classificatory work, for which he received material from all over the world. His classificatory precepts are elaborated in the Philosophia botanica of 1751, an enlarged version of the 365 aphorisms of his Fundamenta botanica of 1735; the other aspects of his work are diffused through his writings. His artificial classification system, initially very popular, was replaced by the ’natural’ system, more slowly in botany than in zoology, and more slowly in England than in some other countries. Current biological nomenclature is based on his Species plantarum, edition 1 (for plants), and Systema naturae, edition 10 (for animals). His codification of botanical terms remains influential. Almost 200 dissertations, most written by Linnaeus, were defended by his students. In these and other less well-known works, including the unpublished Nemesis divina (Stories of Divine Retribution), he covered a wide range of subjects. Quinarian thinking is noticeable in Linnaeus’ work – there are five ranks in systems, five years’ growth in flowers – and in some of the occult works that he knew. He also shows a strong combinatorial bent and a tendency to draw close analogies between the parts of animals and plants.
Logical positivism
Authors: Friedman Michael
Published: September 2018

Logical positivism (logical empiricism, neo-positivism) originated in Austria and Germany in the 1920s. Inspired by late nineteenth- and early twentieth-century revolutions in logic, mathematics and mathematical physics, it aimed to create a similarly revolutionary scientific philosophy purged of the endless controversies of traditional metaphysics. Its most important representatives were members of the Vienna Circle who gathered around Moritz Schlick at the University of Vienna (including Rudolf Carnap, Herbert Feigl, Kurt Gödel, Hans Hahn, Karl Menger, Otto Neurath and Friedrich Waismann) and those of the Society for Empirical Philosophy who gathered around Hans Reichenbach at the University of Berlin (including Walter Dubislav, Kurt Grelling and Carl Hempel). Although not officially members of either group, the Austrian philosophers Ludwig Wittgenstein and Karl Popper were, at least for a time, closely associated with logical positivism.

The logical positivist movement reached its apogee in Europe in the years 1928–34, but the rise of National Socialism in 1933 marked the effective end of this phase. Thereafter, however, many of its most important representatives emigrated to the USA. Here logical positivism found a receptive audience among such pragmatically, empirically and logically minded American philosophers as Charles Morris, Ernest Nagel and W.V. Quine. Thus transplanted to the English-speaking world of ‘analytic’ philosophy it exerted a tremendous influence – particularly in philosophy of science and the application of logical and mathematical techniques to philosophical problems more generally. This influence began to wane around 1960, with the rise of a pragmatic form of naturalism due to Quine and a historical-sociological approach to the philosophy of science due mainly to Thomas Kuhn. Both of these later trends, however, developed in explicit reaction to the philosophy of logical positivism and thereby attest to its enduring significance.
Marxist philosophy of science
Authors: Miller Richard W.
Published: September 2018

Marx’s approach to science is an intriguing combination of respect for the natural sciences and empirical inquiry, determination to go beyond the description of regularities among observable phenomena, and insistence on the inevitable impact of social circumstances on scientific inquiry. Marx thought that the human sciences and the natural sciences are governed by essentially the same methods, that natural-scientific theories give us enhanced insight into mind-independent reality, and that our most fundamental views are subject to revision through scientific inquiry. Yet Marx rejected the ideal of scientific method according to which rational scientific belief is tied to observational data through a canon of rules as general, timeless and complete as the rules of logical deduction. While traditional empiricists emphasize the economical description of empirical regularities which could, in principle, be used to predict the occurrence of observable phenomena, Marx emphasizes the description of underlying causal structures, employing concepts that are typically irreducible to the vocabulary of mere observation, and causal hypotheses that sometimes do not even sketch means of prediction. Similarly, though Marx shared the optimistic view that science gives rise to long-term improvement in our insight into underlying causes, he disagreed with many epistemic optimists in his insistence that scientific inquiry is inevitably and deeply affected by social interests and relations of social power.

Since Marx’s general comments on scientific method are few and scattered, a ‘Marxist philosophy of science’ consists of the further development of this intriguing mixture.
Mechanics, Aristotelian
Authors: Franklin Allan
Published: September 2018

The central feature of Aristotle’s mechanics is his discussion of local motion, a change of place, which he categorizes as either natural or violent. He further divides natural motion into celestial motion, which is uniform, circular and eternal, and terrestrial motion, which is rectilinear (straight up or down), and finite in both time and distance. All motions which are not natural are classified as violent.

For all motion Aristotle required a force in direct contact with the object being moved. We may represent the Aristotelian law of motion by the modern formula: Velocity = Force (motive power)/Resistance, or V=kF/R. In applying this law of motion to falling bodies, Aristotle associated the weight of the body with the force, and the resistance of the air (or other medium) with the resistance. Thus, Aristotle believed that heavy bodies fall faster than light ones.

The problem of what force is actually in contact with the body, and causes it to fall, posed a serious difficulty for Aristotle. Aristotle concluded that elements were created with a tendency to move to their natural place, barring any hindrance or interference. Projectile motion posed a similar problem for Aristotle. In the case of a thrown object, the force was provided by the hand of the thrower as long as the object was in contact with the hand. But one needed an explanation of why the object continued to move once it had left the thrower’s hand. Aristotle concluded that the medium through which the projectile moved provided the force that kept it moving.

Aristotle also regarded both the existence of a void or any motion in it as impossible. A void contains nothing that could sustain the motion of a projectile once it left the projector. In addition, because a void can provide no resistance, the speed of an object in a void would be infinite.