Philosophy: Logic, Epistemology, Philosophy of Science

Logic, Epistemology, and Philosophy of Science cover a wide range of topics and issues including, epistemology, metaphysics, scientific method, science and values, and even the history of science, since there are inevitably many philosophical and conceptual issues present in the development of new ideas. The particular sciences included in this are everything from mathematics, to the natural sciences (biology, chemistry, and physics) to the social sciences (anthropology, economics, and sociology), and various aspects of medicine. Many of the same issues arise in the philosophy of psychology, a field that is often discussed as part of the philosophy of mind or cognitive science, which will be taken here as part of the philosophy of science. In all of these fields, which will be described in more detail, Canadian philosophers have contributed extensively. (For our purposes, Canadian philosophers are those, regardless of nationality or home discipline, who have some significant connection to Canada, typically working on philosophical issues at a Canadian university.)


Logic is concerned with reasoning and valid inference and other topics that grow out of these. An inference is valid when the conclusion follows from the premises. The classic example being: (1) Socrates is a man. (2) All men are mortal. Therefore, Socrates is mortal. It is the form, not the subject matter, that makes it valid. Thus, the following argument with false premises and a false conclusion is nevertheless valid: (1) Socrates is a goat. (2) All goats can fly. Therefore, Socrates can fly. An argument is sound when it is both valid and has true premises. The distinction between the form of an argument and its subject matter is captured by the terms "syntax" and "semantics," respectively. Logicians have developed both extensively and answered many interesting question about their relations. Unsurprisingly, logicians have contributed significantly to the development of linguistics and the understanding of natural language. Perhaps the most famous result in the history of logic is Gödel's incompleteness theorem. It showed that there is no consistent set of axioms (syntax, formal rules for manipulating symbols) strong enough to prove all the truths of arithmetic (semantics, assigning meaning symbols and truth to sentences).

Logic gave birth to fields such as computer science and has in turn been stimulated by it. One of the most important topics of current research is computational complexity, involving, for instance, the number of steps required to prove something. Besides being of theoretical interest, it has practical value, since it is important to know whether a computer can carry out a proof in a reasonable time. Many things can be proven in principle, but require more than the age of the universe to do so. Other topics include modal logic, the study of possibility and necessity, which is of particular interest to metaphysicians. Paraconsistent logic (reasoning with inconsistent assumptions), and many-valued logic (the study of reasoning involving more than the two truth values, true and false) are other flourishing fields. Even though logic is an old and established branch of philosophy, a great deal of research is carried out by mathematicians and computer scientists, as well as by philosophers.

In recent years several Canadian philosophers and logicians have made major contributions to various areas of logic. Some of these include: Alasdair Urquhart (relevance logic, computational complexity), Stephen Cook (computational complexity, "Cook's Theorem"), John Bell (category theory, infinitesimal analysis), Bas Van Fraassen (semantics), Yvon Gauthier (constructive logic), Charles Morgan (formal syntax), Jeff Pelletier (computation), Phillip Kremer (philosophical logic, concept of truth), Calvin Normore, Nicholas Griffin (history of logic), Gregory Moore (history of set theory), David DeVidi (non-standard logics), Richard Zach (history of logic), Verena Huber-Dyson (logic and mathematics), William Harper (probability, decision theory), Brian Chellas (modal logic), William Rozeboom (semantics), William Demopoulos (relation of logic to mathematics), Jean-Pierre Marquis (logic and mathematics), Bernard Linsky (history of Russell's logic), Anil Gupta and Hans Herzberger (semantics of truth and paradoxes), Bryson Brown, Peter Scotch, Ray Jennings, and John Woods (paraconsistent logic), and Colin Howson (Bayesian probability and its relation to deductive logic).


Epistemology (also known as theory of knowledge), is concerned with the nature of evidence and the conditions of rational belief. Questions of epistemology arise everywhere: How can we know anything? Can we justify aesthetic, ethical, or religious beliefs? Scientific beliefs, being the most complex and sophisticated, are perhaps the most philosophically challenging, which leads to a perennial debate: Is science the only source of knowledge? One might argue that if science agrees with common sense or theology or whatever, then there is no problem. But if there is disagreement, the scientific belief is the one best supported by the evidence. Rationality demands that common sense or theology must give way. Needless to say, this is contentious, but the history of the last 400 years has seen science triumph over all rival claims to knowledge.

The epistemology of science overlaps with what is commonly called scientific method: How should we acquire scientific knowledge? How should we test theories? Are theories justified by observations alone, or do other factors (values, simplicity, social conditions) play a role? Most philosophers of science accept the assumptions behind these questions, that is, they do assume that typical scientific theories are indeed justified, especially in the natural sciences. They then try to answer the question: How was it done?; Why, for instance, were the theories of Darwin and Einstein advances on earlier beliefs?; What is the nature of evidence in science, in general? Typically, philosophers would not make the same assumption of theory success when approaching, say, astrology, theology, or even some of the social sciences. Physicists, biologists, and mathematicians certainly seem to be doing something right and the trick is to figure out what it is they actually do that leads to this success. It is surprisingly difficult, but so is explaining how we ride a bicycle, even though it is clear we know how.


Metaphysics is concerned with the more general aspects of reality, features that normally cannot be determined by the empirical sciences. These concern issues such as: the nature of causation, space and time, chance and necessity. As with epistemology, metaphysical issues can be found everywhere (e.g., in ethics, aesthetics, theology), but many of the most interesting issues are connected to the particular sciences. The question of freewill and determinism is a perennial metaphysical issue with ramifications in ethics. It arises in the particular setting of cognitive science, and something similar arises in physics: Is the quantum world deterministic or is there an irreducible element of chance? Majority opinion favours the latter view, but it is very difficult to settle the question and it is quite unlikely that an experiment could decide the matter. Another issue concerns the nature of space and time: Are they entities in their own right, or do they depend on matter and events? The question has been repeatedly modified and refined as physics changes. It is common to say that Newton's absolute space and time have been overthrown by Einstein's relativity, but this is not so. The issue, appropriately re-framed, is still with us and, amazingly, plays an important role in current debates about quantum gravity. Most of the issues within the philosophy of science are issues of epistemology or metaphysics. They are normally considered under special headings.

Methodology and the Structure of Science

While there is general agreement that the natural sciences are highly successful, there is much less agreement on why this is or on how science actually works. Some say theories are built up from observations, while others say theories come first and are tested by their observational consequences. Central questions involve such topics as: explanation, confirmation, and inter-theory relations. In recent years several Canadian philosophers have played leading roles in this area. William Harper and Colin Howson have proposed important accounts of the evidential relation between theory and observation. Margaret Morrison has been influential in her claims that models play a crucial role in mediating between theory and observation. A variety of important contributions have been made by Ian HACKING (experimentation), William Seager (emergence and inter-theory relations), Alex Reuger (emergence), Jean Leroux (theory and observation), James Robert Brown (thought experiments), Paul Bartha (probability and induction), Rob Hudson (experimentation), Paul THAGARD (analogy, methodology in medicine), Letitia Meynell (visualization), Chris Viger (inductive inference), David Davies (thought experiments), and Greg Mikkelson (methodological issues and the environment).


Scientific realism is the doctrine that science aims at the objective truth about reality. It is a commonsense view, but often difficult to uphold. Anti-realists maintain a variety of alternative accounts, such as that science aims only at predicting and systematizing what we can observe, the unobservable being irrelevant. Another type of anti-realism claims that science is a human construction, not a description of an independent realm. Bas van Fraassen contributed much to the anti-realist side. Others such as Cliff Hooker, Paul Churchland, Carl Matheson, André Kukla have been strong proponents of realism. Ian Hacking has been influential in distinguishing ordinary realism from "entity realism," where one accepts the reality of entities, such as electrons, because we can manipulate them, without accepting statements about theoretical entities as also being true. Anjan Chakravartty recently proposed a view he calls semi-realism, in contrast to so-called structural realism, an account that is currently of much interest.


The philosophy of biology is concerned with a variety of issues ranging from the nature of species, the role of biology in human behaviour and culture, the role of genetics, and the relation of biology to physics and chemistry. Philosophers in Canada have made important contributions to most aspects of the philosophy of biology, including work on evolutionary theory by Thomas GOUDGE, Michael Ruse, and Paul Thompson. Ronnie de Sousa, Marc Ereshefsky, Christopher Stevens, Ingo Brigandt, Robert Wilson, Richmond Campbell, John Beatty, Frederic Bouchard, have all contributed significantly to work on species, fitness, and other topics; Denis Walsh, Mohan Matthen have pioneered a statistical interpretation of natural selection. Lisa Gannett has done important work on the notion of biological classification and its social significance, Brian Hall has worked on homology, and Stuart Kauffman on biological complexity. The philosophical physicist, Lee Smolin, has used Darwinian evolution to explain certain features of cosmology.


The philosophy of physics focuses on foundational issues in special and general relativity and the nature of spacetime, in quantum mechanics, in thermodynamics and statistical mechanics, and in other physical theories. The conceptual issues in these various fields are challenging and require technical mastery as well as philosophical skill. Among the more prominent topics are: Is spacetime absolute, that is, a thing in its own right? Or is it a system of relations among physical bodies, so that if there were no bodies and no events, there would be no spacetime? Does the realm of quantum theory exist independently from ourselves and our measurements? Or do we somehow create the very things that we measure, rather than discover what is already there? These questions are as difficult as they are interesting.

A large number of Canadians have made significant contributions to further answering these questions: Richard Arthur (time), Jeffrey Bub (quantum logic, quantum computing), William Demopoulos (quantum logic), Allan Stairs (quantum logic), Robert DiSalle (spacetime), Wayne Myrvold (quantum foundations), Rob Clifton (quantum foundations), David Sharp (quantum foundations), Ferrell Christensen (time), Kent Peacock (spacetime and quantum mechanics), Storrs McCall (time), Mario Bunge (foundational issues in several diverse fields), Chris Smeenk (spacetime), Robert Batterman (models in physics), Doreen Fraser (quantum field theory), Steve Weinstein (quantum gravity), Alex Reuger (quantum mechanics), Robert Coleman and Herbert Korte (spacetime), Josh Mozersky (time), Dan MacArthur (quantum theory), Joseph Berkovitz (quantum mechanics), Andrew Wayne (quantum field theory), Jessica Wilson (classical mechanics), Steve Savitt (time), and Margaret Morrison (symmetry, unification). A number of Canadian physicists have contributed significantly to philosophical aspects of physics: Lee Smolin (spacetime, cosmology), John Sipe (quantum mechanics), Robert Spekkens (quantum mechanics).

In recent years there has been much fruitful interaction between physicists and philosophers. To some extent this is because issues that were dismissed by physicists as "metaphysical" have turned out to have experimental consequences. The moral to draw from this is that the boundary between science and philosophy is rather fuzzy. Philosophers and physicists may emphasize different things, but they are engaged in a common pursuit.

Cognitive Science

Increasingly, philosophers have engaged with cognitive science -- the study of mental operations in their cognitive rather than purely behavioural or neurological aspects. At one time, such interaction was confined to the question of determinism. John Thorp and Ted Honderich were important contributors. More recently, philosophers have not only analysed and conceptually explored cognitive psychology and its methodologies, but also contributed key ideas to psychology. For example, Patricia CHURCHLAND has been a central figure in the integration of neurophysiology and philosophy, and Paul Churchland has contributed importantly to the study of learning. Zenon Pylyshyn, Ausonio Marras, and Paul Thagard studied the conceptual apparatus of cognitive science. A wide range of significant contributions have come from Ronnie de Sousa (emotions), Mohan Matthen (perception), Jim McGilvray (Chomsky and linguistics), William Seager (consciousness), Robert Wilson (externalist theories of mind), Evan Thompson (enactive theories of mind), Rob Stainton (language and mind), and Andrew Brooke (cognition). Intensive and well-known studies of more circumscribed concepts have been undertaken by Donald Dedrick and Kathleen Akins (colour and colour vision), Ian Gold (cognitive deficits), Luc Faucher and Tim Schroeder (emotion), Diana Raffman (music perception), and Daniel Kahneman (reasoning heuristics, Nobel Prize in Economics). Notable recent arrivals to Canada include Murat Aydede (consciousness, pain) and Eric Margolis (concepts).


The philosophy of mathematics is concerned with metaphysical questions concerning the nature of mathematical objects and with epistemic questions concerning how we acquire knowledge of them. Since we do not see or otherwise make contact with mathematical entities (numbers, sets, functions), as we do with physical objects (rocks, planets, electrons), these turn out to be highly puzzling questions. How, after all, do we come to know anything about numbers? The spectrum of views is very wide, from thinking mathematical objects are objectively real and independent from us (Platonism) to thinking they are somehow a human creation. It is commonly thought that the one and only source of evidence in mathematics is proof, understood to be a logical derivation from axioms or first principles. But what about evidence from physics or from diagrams? And what about very long and complex computer proofs, which we can't, strictly speaking, follow, because of their enormous length?

Canadian philosophers of mathematics and mathematicians who work on these philosophical issues include: Michael Hallett (Hilbert and formalism), Emily Carson (Kantian approaches), John Bell (topos theory, non-stand mathematics), William Demopoulos (Frege and logicism), Andrew Irvine (naturalism), Jean-Pierre Marquis (category theory), Yvon Gauthier (constructive approaches), Mathieu Marion (finitism, Wittgenstein), Elaine Landry (category theory), Bernard Linsky (naturalism and Platonism), Alasdair Urquhart (formalism, constructivism), James Robert Brown (visualization, Platonism), Sarah Hoffman (fictionalism), and Michael Slawinski (nature of applied mathematics).


Although ethical issues arising from clinical practice in medicine have captured the most philosophical attention, crucial and important epistemological and methodological issues are of fundamental and crucial importance to clinical and scientific medicine. Medicine is a broad and varied enterprise. Areas such as physiology, haematology (the study of blood), immunology (the study of the immune system and immune responses), endocrinology (the study of hormone systems) and medical genetics share similar methodologies and epistemological features with non-medical biological sciences. On the other hand, clinical practice areas such as family medicine are quite dissimilar to non-medical biological sciences and medical sciences themselves, such as those mentioned above. As a result, different philosophical issues arise in clinical medicine and medical sciences. For example, clinical medicine relies heavily on randomised controlled trials (RCTs) to determine the efficacy of pharmaceutical and lifestyle interventions. Philosophers of science have recently questioned the logical, mathematical (probabilistic and statistical) and epistemological assumptions used to justify reliance on RCTs. Medical sciences rely much less on RCTs and employ models and theories to understand and explain the nature, function and malfunction of the various organs, cells, fluids, proteins and systems (e.g., the menstrual cycle) of the body. Philosophers of science have contributed significantly to the understanding of the nature of such models and theories and the powerful role they play in explaining and predicting aspects of health, disease and therapy.

Canadian philosophers have made seminal and important contributions to all of these issues: Paul Thompson (Evidence Based Medicine (EBM), RCTs, and models and theories), Robyn Blume (EBM and RCTs), Kirstin Borgenson (EBM, RCTs and alternative medicine), Ross Upshur (EBM, RCTs, time series analysis and data-base evidence), Myra Goldman (EMB and RCTs). Susan Sherwin and Francoise Baylis have done extensive work on bioethics, often tying it to issues of medical methodology. Paul Thagard and Charles Weijer have both contributed to a wide variety of methodological issues in medicine.

Social Science

The social sciences (including: economics, sociology, history, and anthropology) are often distinguished from the natural sciences and thought to be fundamentally different. Humans are self-interpreting and our beliefs about ourselves can have an effect on ourselves. By contrast, our beliefs about electrons presumably have no effect on how electrons behave. The opposing view takes the social sciences to be like the natural sciences, subject to the same general methods. In either case, questions of objectivity are central to philosophical concern with the social sciences. In addition, the individual social sciences have their own particular issues. Thus, is game theory a useful tool for economics, or does it miss too much of real human concern? Can different human cultures be understood from the outside, or must true understanding only come by "going native"?

Canadian philosophers addressing these issues include: Charles TAYLOR(explanation of behaviour), David Braybrooke (methodology, democratic theory), Frank Cunningham (objectivity, democratic theory), Jonathan Bennett (rationality), William DRAY (historical understanding), Robert Nadeau (economics), Ian Jarvie (objectivity), Alison Wylie (feminism, anthropology, archaeology), Karyn Freedman (feminism, methodology), Alex Michalos (quality of life, social values), Joseph Berkovitz (decision theory, economics), Oliver Schulte (game theory), Margaret Schabas (history of economics), and Ian Hacking (social kinds, transient mental illness).

Science and Values

Values can arise in the sciences in several different ways. Some of these are ethical, others aesthetic, some are more social and political, and yet others are epistemic. For instance, how should laboratory animals be treated, or should human subject give informed consent?, are questions of procedure that seem irrelevant to the content of the resulting theories. However, values can also make it into the very content of a theory, as clearly happens when we consider notions of health and disease. What counts as a disease is an inextricable mix of biological fact and social norms about what is desirable. Sexist and racist assumptions are clearly present in past theories, and possibly in present theories, as well. Values of an epistemic variety can also arise in the methodology of science, as in the question: Should the simplicity of a theory count as evidence in its favour? The topic of science and values is one of the more controversial areas of philosophy of science. Some maintain that good science must be "value-free," while others claim that values are inevitable, even necessary, but they should be the right values.

Much work on this has been done by Kathleen Okruhlik and Alison Wylie (feminist critiques), Lisa Gannett (concept of race), Michael Ruse (science and religion, sociobiology and politics), James Robert Brown (commercialization of medical research), and Yiftach Fehige (science and religion, sexuality).

History, Philosophy, and Sociology of Science

Many philosophers, as well as historians and sociologists of science, see an intimate relation among history, philosophy, and sociology of science, saying they can best be understood by looking at the whole, interlocking structure. There remains a great deal of debate among them, however, as to the relative importance of the components. Everyone, for instance, acknowledges that social factors are always in the background, but do they play a significant role in determining scientific belief? And what about philosophical beliefs, say in determinism, that seem to guide theory construction in physics? Are such beliefs legitimate in the scientific enterprise, or do they merely impede it?

Canadians have been active contributors in this venture, and they include Richard Arthur (Leibniz), Robert E. Butts (Whewell, Kant, historical methodology), Robert McRae (Leibniz), William Shea (Galileo), John Nicholas (Descartes, Kuhn), Jagdish Hattiangadi (historical methodology), Michael Ruse (Darwin), Margaret Morrison (history of genetics), Ian Hacking (probability theory, historical methodology); Kathleen Okruhlik (Newton, Leibniz), Yves Gingras (modern physics, scientific institutions), Gordon McOuat (history of biology), Andrew Reynolds (biology, Pierce), Sergio Sismondo (sociology of knowledge), David Hyder (19th C science), Brian Baigrie (Descartes, Scientific Revolution), Rhonda Martens (Kepler), John Beatty (Darwin), Alan Richardson (19th and 20th C science and philosophy), Mélanie Frappier (history of quantum mechanics), Margaret Osler, Catherine Wilson (17th C science and philosophy), Margaret Schabas (history of economics), Lee Smolin (sociology of physics research), J.J. MacIntosh (Boyle, science and religion), François Duchesneau (Descartes, Locke). Andre Kukla, James Robert Brown, and Sergio Seismondo have written extensively on the role of social factors in science.


Most contributions to the philosophy of science stem from philosophers located in various university departments of philosophy in Canada and throughout the world. Two Canadian departments stand out in the field of philosophy of science, The University of Western Ontario and The University of Toronto, and are among the best philosophy of science groups in the world. There are also some specialized departments or programmes with a number of excellent philosophers of science, including the Institute for the History and Philosophy of Science, University of Toronto; Science and Technology Studies, York University; and the History of Science and Technology Programme, University of King's College, Halifax.

There are important developments outside philosophy units, as well. The Perimeter Institute for Theoretical Physics in Waterloo, Ontario devotes some of its resources to philosophical issues. The founding Director, Howard Burton (trained in both philosophy and physics), successfully promoted this direction of research, which has been very fruitful. Several members of the permanent staff (Lee Smolin, Lucien Hardy, Christopher Fuchs, Rob Spekkens) and numerous visitors pursue philosophical and foundational issues. Some of the best recent work in the philosophy and foundations of physics has stemmed from this institute.

Two important institutions have recently coming into being. One of these is funded to a significant level by the Social Sciences and Humanities Research Council of Canada grant, Situating Science, the Cluster for the Humanistic and Social Studies of Science. When it has a permanent home, it will be a major centre for history, philosophy, and social studies of science. Much of its funding will be directed toward sponsorship of summer workshops, conferences, and postdoctoral fellowships.

The second new institution is the The Rotman Institute for Science and Values, which is located within the Department of Philosophy at The University of Western Ontario but solicits membership nominations from around the world. Its purpose is to examine both those values that are constitutive of science and those that inform the larger culture within which science is pursued, including ethical, socio-political, economic, legal, and aesthetic values. The Institute's mandate includes the hosting of visiting scholars and postdocs, conferences, and speakers series. Through these activities and others, the Institute is expected to contribute to both scholarly and public policy debates related to science and values.

In general, logic and philosophy of science are pursued at a very high level in Canada. In part this is because this important field of philosophy enjoys strong support within philosophy departments and also benefits from public support, especially through funding agencies such as Social Sciences and Humanities Research Council of Canada. What is probably underappreciated is the role philosophers of science could usefully play in matters of general public concern, such as the relation between science and religion, or the precise role of values in race or gender research. It is to be hoped that philosophers of science become more actively involved in the future.