Philosophy of medicine

Last updated

The philosophy of medicine is a branch of philosophy that explores issues in theory, research, and practice within the field of health sciences. [1] More specifically in topics of epistemology, metaphysics, and medical ethics, which overlaps with bioethics. Philosophy and medicine, both beginning with the ancient Greeks, have had a long history of overlapping ideas. It was not until the nineteenth century that the professionalization of the philosophy of medicine came to be. [2] In the late twentieth century, debates among philosophers and physicians ensued of whether the philosophy of medicine should be considered a field of its own from either philosophy or medicine. [3] A consensus has since been reached that it is in fact a distinct discipline with its set of separate problems and questions. In recent years there have been a variety of university courses, [4] [5] journals, [6] [7] [8] [9] books, [10] [11] [12] [13] textbooks [14] and conferences dedicated to the philosophy of medicine.

Contents

Epistemology

Epistemology is a branch in the philosophy of medicine that is concerned with knowledge. [15] The common questions asked are "What is knowing or knowledge?", "How do we know what we know?", "What is it we know when we claim we know". [16] Philosophers differentiate theories of knowledge into three groups: knowledge of acquaintance, competence knowledge, and propositional knowledge. The knowledge of acquaintance is to be familiar with an object or event. To best explain this would be, a surgeon would need to know the human anatomy before operating on the body. Competence of knowledge is to use known knowledge to perform a task skillfully. The surgeon must know how to perform the surgical procedure before executing it. Propositional knowledge is explanatory, it pertains to certain truths or facts. If the surgeon is performing on the heart it must know the physiological function of the heart before the surgery is performed. [17]

Metaphysics

Metaphysics is the branch of philosophy that examines the fundamental nature of reality including the relationship between mind and matter, substance and attribute, and possibility and actuality. [18] The common questions asked within this branch are "What causes health?" and "What causes disease?". There is a growing interest in the metaphysics of medicine, particularly the idea of causality. [19] 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. [20] The scientific processes used to generate causal knowledge give clues to the metaphysics of causation. For example, the defining feature of randomized controlled trials (RCTs) is that they are thought to establish causal relationships, whereas observational studies do not. [21] In this instance, causation can be considered as something which is counterfactually dependent, i.e. the way RCTs differ from observational studies is that they have a comparison group in which the intervention of interest is not given.

Ontology of medicine

There is a large body of work on the ontology of biomedicine, including ontological studies of all aspects of medicine. Ontologies of specific interest to the philosophy of medicine include, for instance: (1) the ontological revolution which made modern science, in general, possible, (2) Cartesian dualism which makes modern medicine, in particular, possible, (3) the monogenetic conception of disease which has informed clinical medicine for a century or so [22] and also the chemical and biological pathways which underlie the phenomena of health and disease in all organisms, (4) the conceptualization of entities such as ‘placebos’ and ‘placebo effects’.

The Ontology of General Medical Science

The Ontology of General Medical Science (OGMS) is an ontology of entities involved in a clinical encounter. It includes a set of logical definitions of very general terms that are used across medical disciplines, including: 'disease', 'disorder', 'disease course', 'diagnosis', and 'patient'. The scope of OGMS is restricted to humans, but many terms can be applied also to other organisms. OGMS provides a formal theory of disease that is elaborated further by specific disease ontologies which extend it, including the Infectious Disease Ontology (IDO) and the Mental Disease Ontology.[ citation needed ]

Cartesian dualism

René Descartes made ontological space for modern medicine by separating body from mind – while mind is superior to body as it constitutes the uniqueness of the human soul (the province of theology), body is inferior to mind as it is mere matter. Medicine simply investigated(s) the body as machine. While Cartesian dualism dominates clinical approaches to medical research and treatment, the legitimacy of the split between mind and body has been consistently challenged from a variety of perspectives. [23] [24]

Nosology and the monogenic conception of disease

Modern medicine, unlike Galenic medicine (which dealt with humours), is mechanistic. For example, when a bit of solid matter such as a poison or a worm impacts upon another bit of matter (when it enters the human body), this sets off a chain of motions, giving rise to disease, just as when one billiard ball knocks into another billiard, the latter is set in motion. When the human body is exposed to the solid pathogen, it falls ill, giving rise to the notion of a disease entity. Later in the history of modern medicine, particularly by the late nineteenth and twentieth centuries, in nosology (which is the classification of disease), the most powerful is the etiogically-defined approach as can be found in the monogenic conception of disease which covers not only infectious agents (bacteria, viruses. fungi, parasites, prions) but also genetics, poisons. While clinical medicine is concerned with the ill health of the individual patient when s/he has succumbed to disease, epidemiology is concerned with the pattern of diseases in populations in order to study their causes as well as how to manage, control, ameliorate the problems identified under study.

Clinical medicine, as presented above, is part of a reductionist approach to disease, based ultimately on Cartesian dualism which says that the proper study of medicine is an investigation of the body when the latter is viewed as machine. A machine can exhaustively be broken down into its component parts and their respective functions; in the same way, the dominant approach to clinical research and treatment assumes the human body can be broken down/analysed in terms of its component parts and their respective functions, such as its internal and external organs, the tissues and bones of which they are composed, the cells which make up the tissues, the molecules which constitute the cell, down to the atoms (the DNA sequences) which make up the cell in the body.

Placebo

Placebos and placebo effects have generated years of conceptual confusion about what kinds of thing they are. [25] [26] [27] [28] [29] Example definitions of a placebo may refer to their inertness or pharmacological inactivity in relation to the condition they are given for. Similarly, example definitions of placebo effects may refer to the subjectivity or the non-specificity of those effects. [30] These type of definition suggest the view that when given a placebo treatment, one may merely feel better while not being ‘really’ better.

The distinctions at work in these types of definition: between active and inactive/inert, specific and non-specific, and subjective and objective, have been problematized. [25] [31] [32] For instance, if placebos are inactive or inert, then how do they cause placebo effects? More generally, there is scientific evidence from research investigating placebo phenomena which demonstrates that, for certain conditions (such as pain), placebo effects can be both specific and objective in the conventional sense. [33]

Other attempts to define placebos and placebo effects therefore shift focus away from these distinctions and onto therapeutic effects that are caused or modulated by the context in which a treatment is delivered and the meaning that different aspects of treatments have for patients. [34] [35]

The problems arising over the definition of placebos and their effects may be said to be the heritage of Cartesian dualism, under which mind and matter are understood as two different substances. Furthermore, Cartesian dualism endorses a form of materialism which permits matter to have an effect on matter, or even matter to work on mind (epiphenomenalism, which is the raison d’être of psycho-pharmacology), but does not permit mind to have any effect on matter. This then means that medical science has difficulty in entertaining even the possibility that placebo effects are real, exist and may be objectively determinable and finding such reports difficult if not impossible to comprehend and/or accept. Yet such reports which appear to be genuine pose a threat to Cartesian dualism which provides the ontological underpinning for biomedicine especially in its clinical domain. [22]

How Physicians Practice Medicine

Evidence-based medicine

Evidence-based medicine (EBM) is underpinned by the study of the ways in which we can gain knowledge regarding key clinical questions such as the effects of medical interventions, the accuracy of diagnostic tests, and the predictive value of prognostic markers. EBM provides an account of how medical knowledge can be applied to clinical care. EBM not only provides clinicians with a strategy for best practice, but also, underlying that, a philosophy of evidence.

Interest in the EBM philosophy of evidence has led philosophers to consider the nature of EBM’s hierarchy of evidence, which rank different kinds of research methodology, ostensibly, by the relative evidential weight they provide. While Jeremy Howick provides a critical defense of EBM, [11] most philosophers have raised questions about its legitimacy. Key questions asked about hierarchies of evidence concern the legitimacy of ranking methodologies in terms of the strength of support that they supply; [36] [37] how instances of particular methods may move up and down a hierarchy; [38] as well as how different types of evidence, from different levels in the hierarchies, should be combined. Critics of medical research have raised numerous questions regarding the unreliability of medical research. [39]

Additionally the epistemological virtues of particular aspects of clinical trial methodology have been examined, mostly notably the special place that is given to randomisation, [40] [41] [42] the notion of a blind experiment and the use of a placebo control.

Notable philosophers of medicine

Related Research Articles

Alternative medicine is any practice that aims to achieve the healing effects of medicine despite lacking biological plausibility, testability, repeatability or evidence of effectiveness. Unlike modern medicine, which employs the scientific method to test plausible therapies by way of responsible and ethical clinical trials, producing repeatable evidence of either effect or of no effect, alternative therapies reside outside of medical science and do not originate from using the scientific method, but instead rely on testimonials, anecdotes, religion, tradition, superstition, belief in supernatural "energies", pseudoscience, errors in reasoning, propaganda, fraud, or other unscientific sources. Frequently used terms for relevant practices are New Age medicine, pseudo-medicine, unorthodox medicine, holistic medicine, fringe medicine, and unconventional medicine, with little distinction from quackery.

<span class="mw-page-title-main">Epistemology</span> Branch of philosophy concerning knowledge

Epistemology is the branch of philosophy concerned with knowledge. Epistemologists study the nature, origin, and scope of knowledge, epistemic justification, the rationality of belief, and various related issues. Debates in (contemporary) epistemology are generally clustered around four core areas:

  1. The philosophical analysis of the nature of knowledge and the conditions required for a belief to constitute knowledge, such as truth and justification
  2. Potential sources of knowledge and justified belief, such as perception, reason, memory, and testimony
  3. The structure of a body of knowledge or justified belief, including whether all justified beliefs must be derived from justified foundational beliefs or whether justification requires only a coherent set of beliefs
  4. Philosophical skepticism, which questions the possibility of knowledge, and related problems, such as whether skepticism poses a threat to our ordinary knowledge claims and whether it is possible to refute skeptical arguments

Evidence-based medicine (EBM) is "the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients." The aim of EBM is to integrate the experience of the clinician, the values of the patient, and the best available scientific information to guide decision-making about clinical management. The term was originally used to describe an approach to teaching the practice of medicine and improving decisions by individual physicians about individual patients.

<span class="mw-page-title-main">Homeopathy</span> Pseudoscientific system of alternative medicine

Homeopathy or homoeopathy is a pseudoscientific system of alternative medicine. It was conceived in 1796 by the German physician Samuel Hahnemann. Its practitioners, called homeopaths, believe that a substance that causes symptoms of a disease in healthy people can cure similar symptoms in sick people; this doctrine is called similia similibus curentur, or "like cures like". Homeopathic preparations are termed remedies and are made using homeopathic dilution. In this process, the selected substance is repeatedly diluted until the final product is chemically indistinguishable from the diluent. Often not even a single molecule of the original substance can be expected to remain in the product. Between each dilution homeopaths may hit and/or shake the product, claiming this makes the diluent "remember" the original substance after its removal. Practitioners claim that such preparations, upon oral intake, can treat or cure disease.

Psychosomatic medicine is an interdisciplinary medical field exploring the relationships among social, psychological, behavioral factors on bodily processes and quality of life in humans and animals.

<span class="mw-page-title-main">Placebo</span> Substance or treatment of no therapeutic value

A placebo can be roughly defined as a sham medical treatment. Common placebos include inert tablets, inert injections, sham surgery, and other procedures.

<span class="mw-page-title-main">Mind–body dualism</span> Philosophical theory

In the philosophy of mind, mind–body dualism denotes either the view that mental phenomena are non-physical, or that the mind and body are distinct and separable. Thus, it encompasses a set of views about the relationship between mind and matter, as well as between subject and object, and is contrasted with other positions, such as physicalism and enactivism, in the mind–body problem.

Bioethics is both a field of study and professional practice, interested in ethical issues related to health, including those emerging from advances in biology, medicine, and technologies. It proposes the discussion about moral discernment in society and it is often related to medical policy and practice, but also to broader questions as environment, well-being and public health. Bioethics is concerned with the ethical questions that arise in the relationships among life sciences, biotechnology, medicine, politics, law, theology and philosophy. It includes the study of values relating to primary care, other branches of medicine, ethical education in science, animal, and environmental ethics, and public health.

Mind–body interventions (MBI) or mind-body training (MBT) are health and fitness interventions that are intended to work on a physical and mental level such as yoga, tai chi, and Pilates.

A nocebo effect is said to occur when negative expectations of the patient regarding a treatment cause the treatment to have a more negative effect than it otherwise would have. For example, when a patient anticipates a side effect of a medication, they can experience that effect even if the "medication" is actually an inert substance. The complementary concept, the placebo effect, is said to occur when positive expectations improve an outcome. The nocebo effect is also said to occur in someone who falls ill owing to the erroneous belief that they were exposed to a toxin, e.g. SARS-CoV-2 vaccine adulterants, or to a physical phenomenon they believe is harmful, such as EM radiation.

In philosophy, the Cartesian Self, or Cartesian subject, a concept developed by the philosopher René Descartes within his system of mind–body dualism, is the term provided for a separation between mind and body as posited by Descartes. In the simple view the self can be viewed as just the mind which is separate from the body as well as from the outside world. The simple self, the mind, also stands to be capable of thinking about itself and its existence. The self when seen as a compound is when it can be interpreted as being a whole human being - body and mind - with the body being an extension of the mind. It is distinct from the Cartesian other, anything other than the Cartesian self, yet the human-being version, union of body and mind, of the self is capable of interaction with the Cartesian Other through extension. According to Descartes, there is a divide intrinsic to consciousness such that one Individual's self is the only thing one can know to certainly exist - since one is not capable of knowing whether other minds exist or are able to think.

The philosophy of biology is a subfield of philosophy of science, which 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, philosophy of biology only emerged as an independent field of philosophy in the 1960s and 1970s, associated with the research of David Hull. Philosophers of science then began paying increasing attention to biology, from the rise of Neodarwinism in the 1930s and 1940s to the discovery of the structure of DNA in 1953 to more recent advances in genetic engineering. Other key ideas include the reduction of all life processes to biochemical reactions, and the incorporation of psychology into a broader neuroscience.

Assay sensitivity is a property of a clinical trial defined as the ability of a trial to distinguish an effective treatment from a less effective or ineffective intervention. Without assay sensitivity, a trial is not internally valid and is not capable of comparing the efficacy of two interventions.

Kazem Sadegh-Zadeh was a German analytic philosopher of medicine of Iranian descent. He was the first ever professor of philosophy of medicine at a German university and has made significant contributions to the philosophy, methodology, and logic of medicine since 1970.

A hierarchy of evidence, comprising levels of evidence (LOEs), that is, evidence levels (ELs), is a heuristic used to rank the relative strength of results obtained from experimental research, especially medical research. There is broad agreement on the relative strength of large-scale, epidemiological studies. More than 80 different hierarchies have been proposed for assessing medical evidence. The design of the study and the endpoints measured affect the strength of the evidence. In clinical research, the best evidence for treatment efficacy is mainly from meta-analyses of randomized controlled trials (RCTs). Systematic reviews of completed, high-quality randomized controlled trials – such as those published by the Cochrane Collaboration – rank the same as systematic review of completed high-quality observational studies in regard to the study of side effects. Evidence hierarchies are often applied in evidence-based practices and are integral to evidence-based medicine (EBM).

The word placebo was used in a medicinal context in the late 18th century to describe a "commonplace method or medicine" and in 1811 it was defined as "any medicine adapted more to please than to benefit the patient". Although this definition contained a derogatory implication, it did not necessarily imply that the remedy had no effect.

The Centre for Evidence-Based Medicine (CEBM), based in the Nuffield Department of Primary Care Health Sciences at the University of Oxford, is an academic-led centre dedicated to the practice, teaching, and dissemination of high quality evidence-based medicine to improve healthcare in everyday clinical practice. CEBM was founded by David Sackett in 1995. It was subsequently directed by Brian Haynes and Paul Glasziou. Since 2010 it has been led by Professor Carl Heneghan, a clinical epidemiologist and general practitioner.

A pragmatic clinical trial (PCT), sometimes called a practical clinical trial (PCT), is a clinical trial that focuses on correlation between treatments and outcomes in real-world health system practice rather than focusing on proving causative explanations for outcomes, which requires extensive deconfounding with inclusion and exclusion criteria so strict that they risk rendering the trial results irrelevant to much of real-world practice.

<span class="mw-page-title-main">Jeremy Howick</span>

Jeremy Howick is a Canadian-born, British residing clinical epidemiologist and philosopher of science. He researches evidence-based medicine, clinical empathy and the philosophy of medicine, including the use of placebos in clinical practice and clinical trials. He is the author of over 100 peer-reviewed papers, as well as two books, The Philosophy of Evidence-Based Medicine in 2011, and Doctor You in 2017. In 2016, he received the Dawkins & Strutt grant from the British Medical Association to study pain treatment. He publishes in Philosophy of Medicine and medical journals. He is a member of the Sigma Xi research honours society.

The infinitesimally low concentration of homeopathic preparations, which often lack even a single molecule of the diluted substance, has been the basis of questions about the effects of the preparations since the 19th century. Modern advocates of homeopathy have proposed a concept of "water memory", according to which water "remembers" the substances mixed in it, and transmits the effect of those substances when consumed. This concept is inconsistent with the current understanding of matter, and water memory has never been demonstrated to exist, in terms of any detectable effect, biological or otherwise.

References

  1. ↑ Wulff, Henrik R.; Pedersen, Stig Andur; Rosenberg, Raben (1986). Philosophy of Medicine an Introduction.
  2. ↑ Ankeny, Rachel A.; Reiss, Julian (2016-06-06). "Philosophy of Medicine".{{cite journal}}: Cite journal requires |journal= (help)
  3. ↑ Caplan, Arthur L. (March 1992). "Does the philosophy of medicine exist?". Theoretical Medicine . 13 (1): 67–77. doi:10.1007/BF00489220. ISSN   0167-9902. PMID   1604434. S2CID   22710233.
  4. ↑ Durham University History and Philosophy of Medicine
  5. ↑ University of Oxford course on the History and Philosophy of Medicine
  6. ↑ Springer Journal, Medicine, Health Care, and Philosophy
  7. ↑ Oxford Journals, Journal of Medicine and Philosophy
  8. ↑ Springer Journal, Theoretical Medicine and Bioethics
  9. ↑ Pijush Kanti Bhattacharjee (2014). "Working Philosophy of All Medicines" (PDF). International Journal of Advanced Engineering and Global Technology. 2 (7): 823–827.
  10. ↑ Dov M. Gabbay (2011-02-23). Philosophy of Medicine. Science Direct. ISBN   978-0-444-51787-6.
  11. 1 2 Jeremy Howick (2011-02-23). The Philosophy of Evidence-based Medicine. John Wiley & Sons. ISBN   978-1-4443-4266-6.
  12. ↑ Edmund D. Pellegrino. The Philosophy of Medicine Reborn. University of Notre Dame Press.
  13. ↑ Keekok Lee (2013-02-23). "The Philosophical Foundations of Modern Medicine". Theoretical Medicine and Bioethics. 34 (5): 437–440. doi:10.1007/s11017-013-9253-5. S2CID   141742194.
  14. ↑ Stegenga, Jacob (2018). Care and Cure: An Introduction To Philosophy of Medicine. University of Chicago Press. ISBN   9780226595030.
  15. ↑ "epistemology | Definition, Nature, Problems, & History". Encyclopedia Britannica. Retrieved 2019-05-01.
  16. ↑ Bishop, Michael A.; Trout, J. D.; Trout, Professor of Philosophy and Psychology J. D. (2005). Epistemology and the Psychology of Human Judgment. Oxford University Press, USA. ISBN   9780195162295.
  17. ↑ Khushf, George (2013-10-01). "A Framework for Understanding Medical Epistemologies". The Journal of Medicine and Philosophy: A Forum for Bioethics and Philosophy of Medicine. 38 (5): 461–486. doi: 10.1093/jmp/jht044 . ISSN   0360-5310. PMID   24038643.
  18. ↑ "metaphysics", The Free Dictionary, retrieved 2019-05-01
  19. ↑ Worrall J (2011). "Causality in medicine: Getting back to the Hill top". Preventive Medicine. 53 (4–5): 235–238. doi:10.1016/j.ypmed.2011.08.009. PMID   21888926.
  20. ↑ Cartwright N (2009). "What are randomised controlled trials good for?" (PDF). Philosophical Studies. 147 (1): 59–70. doi: 10.1007/s11098-009-9450-2 . S2CID   56203659.
  21. ↑ Bradford Hill A (1965). "The Environment and Disease: Association or Causation?". Proceedings of the Royal Society of Medicine. 58 (5): 295–300. doi:10.1177/003591576505800503. PMC   1898525 . PMID   14283879.
  22. 1 2 Lee, K., 2012. The Philosophical Foundations of Modern Medicine, London/New York, Palgrave/Macmillan.
  23. ↑ Ewen, Stuart (2009). Typecasting: On the arts and sciences of human inequality. Seven Stories Press.
  24. ↑ Eagleton, Terry (2016). Materialism. Yale.
  25. 1 2 Grünbaum A (1981). "The Placebo Concept". Behaviour Research and Therapy. 19 (2): 157–167. doi:10.1016/0005-7967(81)90040-1. PMID   7271692.
  26. ↑ Gøtzsche P.C. (1994). "Is there logic in the placebo?". Lancet. 344 (8927): 925–926. doi:10.1016/s0140-6736(94)92273-x. PMID   7934350. S2CID   33650340.
  27. ↑ Nunn R (2009). "It's time to put the placebo out of our misery". British Medical Journal. 338: b1568. doi:10.1136/bmj.b1568. S2CID   72382442.
  28. ↑ Turner A (2012). "Placebos" and the logic of placebo comparison". Biology & Philosophy. 27 (3): 419–432. doi:10.1007/s10539-011-9289-8. hdl: 1983/6426ce5a-ab57-419c-bc3c-e57d20608807 . S2CID   4488616.
  29. ↑ Holman, Bennett (2015). "Why Most Sugar Pills are Not Placebos". Philosophy of Science. 82 (5): 1330–1343. doi:10.1086/683817. S2CID   123784995.
  30. ↑ Shapiro, A.K. & Shapiro, E., 1997. The Powerful Placebo, London: Johns Hopkins University Press.
  31. ↑ Miller F.G.; Brody H. (2011). "Understanding and Harnessing Placebo Effects: Clearing Away the Underbrush". Journal of Medicine and Philosophy. 36 (1): 69–78. doi:10.1093/jmp/jhq061. PMC   3916752 . PMID   21220523.
  32. ↑ Howick J (Sep 2009). "Questioning the methodologic superiority of 'placebo' over 'active' controlled trials". American Journal of Bioethics. 9 (9): 34–48. doi:10.1080/15265160903090041. PMID   19998192. S2CID   41559691.
  33. ↑ Benedetti, F., 2009. Placebo Effects: Understanding the mechanisms in health and disease, Oxford: Oxford University Press.
  34. ↑ Moerman, D.E., 2002. Meaning, Medicine, and the "Placebo Effect," Cambridge: Cambridge University Press.
  35. ↑ Thompson J.J.; Ritenbaugh C.; Nichter M. (2009). "Reconsidering the Placebo Response from a Broad Anthropological Perspective". Culture, Medicine and Psychiatry. 33 (1): 112–152. doi:10.1007/s11013-008-9122-2. PMC   2730465 . PMID   19107582.
  36. ↑ La Caze A (2008). "Evidence-Based Medicine Can't Be…". Social Epistemology. 22 (4): 353–379. doi:10.1080/02691720802559438. S2CID   219693849.
  37. ↑ La Caze A (2009). "Evidence-Based Medicine Must Be …". Journal of Medicine and Philosophy. 34 (5): 509–527. doi:10.1093/jmp/jhp034. PMID   19690324.
  38. ↑ Guyatt G.H.; et al. (2008). "GRADE: an emerging consensus on rating quality of evidence and strength of recommendations". British Medical Journal. 336 (7650): 924–6. doi:10.1136/bmj.39489.470347.AD. PMC   2335261 . PMID   18436948.
  39. ↑ Jacob Stegenga (2018), Medical Nihilism, OUP, ISBN   9780198747048
  40. ↑ Papineau D (1994). "The Virtues of Randomization". British Journal for the Philosophy of Science. 45 (2): 437–450. doi:10.1093/bjps/45.2.437.
  41. ↑ Worrall J (2002). "What Evidence in Evidence-Based Medicine?". Philosophy of Science. 69 (3): S316–S330. doi:10.1086/341855. JSTOR   3081103. S2CID   55078796.
  42. ↑ Worrall J (2007). "Why there's no cause to randomize". British Journal for the Philosophy of Science. 58 (3): 451–488. CiteSeerX   10.1.1.120.7314 . doi:10.1093/bjps/axm024.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.