In this article, I introduce the notion of horizon for scientific practice (HSP), representing limits or boundaries within which scientists ply their trade, to facilitate analysis of scientific discovery and progress. The notion includes not only constraints that delimit scientific practice, e.g. of bringing experimentation to a temporary conclusion, but also possibilities that open up scientific practice to additional scientific discovery and to further scientific progress. Importantly, it represents scientific practice as a dynamic and developmental integration of activities to investigate (...) and analyze the natural world. I use the discovery of the clotting factor, thrombin, and the experiments conducted by the Johns Hopkins physiologist, William Howell, on the enzymatic nature of thrombin to illustrate the notion of HSP. In a concluding section, I compare the notion of HSP to other notions for scientific practice proposed in the history and philosophy of science literature. (shrink)

Many theorists, including Nietzsche, Adorno, and Foucault, have regarded genealogy as an important technique for social criticism. But it has been unclear how genealogy can go beyond the accomplishments of other, more mundane, critical methods. I propose a new approach to understanding the critical potential of history. I argue that theorists have been misled by the assumption that if a claim is deserving of criticism, it is because the claim is false. Turning to the criticism of concepts rather than criticism (...) of claims, I expand on the distinction between "descriptive semantics" and "foundational semantics" to show that genealogy can be uniquely qualified to explore the foundations of concepts, and hence to criticize concepts that are problematic in nonobvious ways. (shrink)

Several philosophers have questioned the possibility of a genetic epistemology, an epistemology concerned with the developmental transitions between successive states of knowledge in the individual person. Since most arguments against the possibility of a genetic epistemology crucially depend upon a sharp distinction between the genesis of an idea and its justification, I argue that current philosophy of science raises serious questions about the universal validity of this distinction. Then I discuss several senses of the genetic fallacy, indicating which sense of (...) ‘genesis’ is relevant to epistemology. Next I consider the objection that psychology is irrelevant to epistemology, and that since "genetic epistemology" is really psychology, "genetic epistemology" is irrelevant to a real epistemology. Finally, I take up the objection that nothing discovered in genetic psychology could be relevant to a genetic epistemology. These last two arguments are based upon what I claim to be a mistaken notion of the nature of psychology. Suitably interpreted, psychology can assist genetic epistemology precisely in the way that the history of science assists current philosonhv of science. *I owe considerable thanks to Jann Benson, Ken Freeman, Bernie Rollin and Ron Williams for their helpful discussions concerning many of the issues discussed in this paper. I also wish to thank David Hamlyn, John Heil, William Lycan, Harvey Siegel and an anonymous reviewer for their comments and suggestions. It goes without saying that none of these individuals (especially Hamlyn and Siegel) necessarily agree with me. An earlier version of this paper was read at Colorado State University where the audience's comments were beneficial. (shrink)

As much as assumptions about mechanisms and mechanistic explanation have deeply affected psychology, they have received disproportionately little analysis in philosophy. After a historical survey of the influences of mechanistic approaches to explanation of psychological phenomena, we specify the nature of mechanisms and mechanistic explanation. Contrary to some treatments of mechanistic explanation, we maintain that explanation is an epistemic activity that involves representing and reasoning about mechanisms. We discuss the manner in which mechanistic approaches serve to bridge levels rather than (...) reduce them, as well as the different ways in which mechanisms are discovered. Finally, we offer a more detailed example of an important psychological phenomenon for which mechanistic explanation has provided the main source of scientific understanding. (shrink)

We distinguish three aspects of medical diagnosis: generating new diagnostic hypotheses, selecting hypotheses for further pursuit, and evaluating their probability in light of the available evidence. Drawing on Peirce’s account of abduction, we argue that hypothesis generation is amenable to normative analysis: physicians need to make good decisions about when and how to generate new diagnostic hypothesis as well as when to stop. The intertwining relationship between the generation and selection of diagnostic hypotheses is illustrated through the analysis of a (...) detailed clinical case study. This interaction is not adequately captured by the existing probabilistic, decision-theoretic models of the threshold approach to clinical decision-making. Instead, we propose to conceptualize medical diagnosis in terms of strategic reasoning. (shrink)

Philosophy of science and history of science both have a significant relation to science itself; but what is their relation to each other? That question has been a focal point of philosophical and historical work throughout the second half of this century. An analysis and review of the progress made in dealing with this question, and especially that made in philosophy, is the focus of this thesis. Chapter one concerns logical positivist and empiricist approaches to philosophy of science, and the (...) significance of the criticisms levelled at them by analytic epistemologists such as Willard Quine and 'historicist' philosophers, especially Thomas Kuhn. Chapter two details the attempts by Kuhn and Lakatos to integrate these historicist criticisms with historically oriented philosophy of science, in their separate attempts at providing rational explanations of historical developments. Kuhn's latest work seeks to mend fences with philosophy, but his efforts remain too closely tied to the epistemological approaches strongly criticized in his earlier work. Lakatos' treatment of history is much more subtle than most have understood it to be, but the conception of scientific rationality that arises out of it is transformed into an abstract cultural product, more reminiscent of Hegel's geist than of individual human rationality. Chapters three and four discuss the recommendations of Lakatos and Laudan to historians with regard to historiography, and the actual historiographies and philosophy of history of practicing historians and historians of science. The philosophers' contributions indicate little concern for the historians' own methods, materials, and purposes; and the historians' writings present methodologies for history of science that are independent of the normative demarcations of philosophy of science, pace Lakatos and Laudan. Chapter five develops a philosophical position that fosters a more productive engagement between philosophy and history of science, a 'methodological historicism' that embraces the possibility of an important role for social and political factors in a philosophical study of scientific development. The epistemological relativism that might accompany such a historicist position need not be the radical epistemological anarchism of Feyerabend, though it will allow for a significant underdetermination of scientific development by reason nonetheless. (shrink)

In his influential paper, 'Why Was the Logic of Discovery Abandoned?', Laudan contends that there has been no philosophical rationale for a logic of discovery since the emergence of consequentialism in the 19th century. It is the purpose of this paper to show that consequentialism does not involve the rejection of all types of logic of discovery. Laudan goes too far in his interpretation of the historical shift from generativism to consequentialism, and his claim that the context of pursuit belongs (...) to neither discovery nor justification is based on narrow interpretations of the contexts of discovery and justification. As a result, Laudan draws unwarranted conclusions concerning both the early and contemporary defenders of a logic of discovery. A methodological logic of discovery - which involves self-corrective methods of hypothesis generation that promote the long-term goals of science and which require consequential support for justification - is a type of logic of discovery that survives the shift to consequentialism. (shrink)

Discoveries in physics imply two elements. The firstone is the belief that formal tools, already foundedin the framework of existing mathematical theories,may offer the solution to a puzzling anomaly. Thesecond one is the ability to assign a physical meaningto the adopted formalism, and to consider all itstheoretical implications.Discussing an historical case where the adoption of aparticular formalism represents the real motor of thecreative intuition, we mean to delineate scientificdiscovery both as a discontinuous change with respectto previous achievements and as a (...) linear process ofknowledge enrichment. (shrink)

There are various ``classical'' arguments against abduction as a logic of discovery,especially that (1) abduction is too weak a mode of inference to be of any use, and (2) in basic formulation of abduction the hypothesisis already presupposed to be known, so it is not the way hypotheses are discovered in the first place. In this paper I argue, by bringing forth the idea of strategies,that these counter-arguments are weaker than may appear. The concept of strategies suggests, inter alia, that (...) many inferential moves are taken into account at the same time. This is especially important in abductive reasoning, which is basically a very weak mode of inference. The importance of strategic thinking can already be seen in Charles S.Peirce's early treatments of the topic, and N.R.Hanson's later writings on abduction although they did not use the concept of``strategies.'' On the whole, I am arguing that the focus should be more on methodological processes, and not only on validity considerations, which have dominated the discussion about abduction. (shrink)

The purpose of this dissertation is to contribute to our understanding of scientific theory pursuit by providing a detailed case study on the development of early quantum theory, from roughly 1900 to 1916. I first elaborate on why this case should be considered an instance of piecemeal pursuit by presenting the historical quantum conjectures that were being used in different contexts. These conjectures gave varied interpretations of quantization. By comparing these conjectures, I identify a general quantum postulate that captures the (...) underlying assumption common to all the cases. I argue that it is possible to consider a general postulate about quantization even when its proper application is ambiguous in a given context, and that the postulate can be separated from different elements of the framework being used to investigate it. I show that the quantum postulate can be deemed promising by analysing the support it gains using a Bayesian framework. I first defend the use of such a framework by considering the purported inconsistencies in Planck's introduction of his quantum conjecture and how we should handle these. I then explicate two cases of support for the postulate. First, I show how we can use a particular solution to the Bayesian problem of old evidence to interpret the support the quantum postulate received by accounting for phenomena that had no previous explanation. Finally, I show that the quantum postulate is also supported by a unification argument, where unification is interpreted as informational relevance between the different domains of inquiry. (shrink)

Proceedings of the 2016 "one word" colloquium of the The Philosophical Society of Finland. The word was "Possibility".

Interdisciplinarity is strongly promoted in science policy across the world. It is seen as a necessary condition for providing practical solutions to many pressing complex problems for which no single disciplinary approach is adequate alone. In this article we model multi- and interdisciplinary research as an instance of collective problem solving. Our goal is to provide a basic representation of this type of problem solving and chart the epistemic benefits and costs of researchers engaging in different forms of cognitive coordination. (...) Our findings suggest that typical forms of interdisciplinary collaboration are unlikely to find optimal solutions to complex problems within short time frames and can lead to methodological conservatism. This provides some grounds for both reflecting on current science policy and envisioning more effective scientific practices with respect to interdisciplinary problem solving. (shrink)

This book examines the philosophical conception of abductive reasoning as developed by Charles S. Peirce, the founder of American pragmatism. It explores the historical and systematic connections of Peirce's original ideas and debates about their interpretations. Abduction is understood in a broad sense which covers the discovery and pursuit of hypotheses and inference to the best explanation. The analysis presents fresh insights into this notion of reasoning, which derives from effects to causes or from surprising observations to explanatory theories. The (...) author outlines some logical and AI approaches to abduction as well as studies various kinds of inverse problems in astronomy, physics, medicine, biology, and human sciences to provide examples of retroductions and abductions. The discussion covers also everyday examples with the implication of this notion in detective stories, one of Peirce’s own favorite themes. The author uses Bayesian probabilities to argue that explanatory abduction is a method of confirmation. He uses his own account of truth approximation to reformulate abduction as inference which leads to the truthlikeness of its conclusion. This allows a powerful abductive defense of scientific realism. This up-to-date survey and defense of the Peircean view of abduction may very well help researchers, students, and philosophers better understand the logic of truth-seeking. (shrink)

In the 1950s and 1960s, an interfield interaction between molecular biologists and biochemists integrated important discoveries about the mechanism of protein synthesis. This extended discovery episode reveals two general reasoning strategies for eliminating gaps in descriptions of the productive continuity of mechanisms: schema instantiation and forward chaining/backtracking. Schema instantiation involves filling roles in an overall framework for the mechanism. Forward chaining and backtracking eliminate gaps using knowledge about types of entities and their activities. Attention to mechanisms highlights salient features of (...) this historical episode while providing general reasoning strategies for mechanism discovery. (shrink)

The main thrust of the argument of this thesis is to show the possibility of articulating a method of construction or of synthesis--as against the most common method of analysis or division--which has always been (so we shall argue) a necessary component of scientific theorization. This method will be shown to be based on a fundamental synthetic logical relation of thought, that we shall call inversion--to be understood as a species of logical opposition, and as one of the basic monadic (...) logical operators. Thus the major objective of this thesis is to This thesis can be viewed as a response to Larry Laudan's challenge, which is based on the claim that ``the case has yet to be made that the rules governing the techniques whereby theories are invented (if any such rules there be) are the sorts of things that philosophers should claim any interest in or competence at.'' The challenge itself would be to show that the logic of discovery (if at all formulatable) performs the epistemological role of the justification of scientific theories. We propose to meet this challenge head on: a) by suggesting precisely how such a logic would be formulated; b) by demonstrating its epistemological relevance (in the context of justification) and c) by showing that a) and b) can be carried out without sacrificing the fallibilist view of scientific knowledge. OBJECTIVES: We have set three successive objectives: one general, one specific, and one sub-specific, each one related to the other in that very order. (A) The general objective is to indicate the clear possibility of renovating the traditional analytico-synthetic epistemology. By realizing this objective, we attempt to widen the scope of scientific reason or rationality, which for some time now has perniciously been dominated by pure analytic reason alone. In order to achieve this end we need to show specifically that there exists the possibility of articulating a synthetic (constructive) logic/reason, which has been considered by most mainstream thinkers either as not articulatable, or simply non-existent. (B) The second (specific) task is to respond to the challenge of Larry Laudan by demonstrating the possibility of an epistemologically significant generativism. In this context we will argue that this generativism, which is our suggested alternative, and the simplified structuralist and semantic view of scientific theories, mutually reinforce each other to form a single coherent foundation for the renovated analytico-synthetic methodological framework. (C) The third (sub-specific) objective, accordingly, is to show the possibility of articulating a synthetic logic that could guide us in understanding the process of theorization. This is realized by proposing the foundations for developing a logic of inversion, which represents the pattern of synthetic reason in the process of constructing scientific definitions. (shrink)

The article reports the results from the developmentof four data-driven discovery systems, operating inlinguistics. The first mimics the induction methods ofJohn Stuart Mill, the second performs componentialanalysis of kinship vocabularies, the third is ageneral multi-class discrimination program, and thefourth finds logical patterns in data. These systemsare briefly described and some arguments are offeredin favour of machine linguistic discovery. Thearguments refer to the strength of machines incomputationally complex tasks, the guaranteedconsistency of machine results, the portability ofmachine methods to new tasks and (...) domains, and thepotential machines provide for our gaining newinsights. (shrink)

In this article, I compare two varieties of abduction as reconstructive models for analysing discovery. The first is 'Hansonian abduction', which is based on N. R. Hanson's formulations of abduction. The other is 'Harmanian abduction', the Inference to the Best Explanation (IBE) model, formulated especially by Gilbert Harman. Peter Lipton has analysed processes of discovery on the basis of his developed form of Harmanian abduction. I argue that Hansonian abduction would, however, be a more apt model for this purpose. As (...) an example, I reconstruct, in a Hansonian manner, Ignaz Semmelweis's research on childbed fever and compare it to the IBE reconstruction of Lipton. I argue that Hansonian abduction is in accordance with Lipton's aim of taking into account the distinction between actual and potential explanations on the one hand, and between likely and lovely explanations on the other. I maintain that a developed version of Hansonian abduction combined with loveliness gives an important, new conceptual means for analysing processes of discovery. (shrink)

En este trabajo, se presentan y analizan, a modo de debate ciertas problemáticas inherentes a la elección de los investigadores al momento de definir el eje epistemológico de su investigación: pregunta o hipótesis. Durante mucho tiempo se ha considerado que estos componentes deben estar presentes simultáneamente en un proyecto de investigación, cuando en realidad pertenecen a lógicas diversas. Aquí planteamos la necesidad de reflexionar sobre ejes epistemológicos distintos y a la vez potentes para iniciar una investigación. Pero la co-presencia de (...) ambos ejes en la investigación le quita solidez y consistencia epistemológica a un proyecto de investigación, dado que la racionalidad subyacente con que se construye cada uno de estos ejes difiere entre sí.This paper presents and analyses by way of an open debate certain issues inherent to the choice of researchers when defining the epistemological axis of his research: question or hypothesis. It has been long considered that these components must be present simultaneously in a research project, when in fact belong to different epistemological axes. Each one is different and powerful enough to start some research. But the simultaneous presence of both axes removes epistemological strength and consistency to a research project because the different rationale of each of these axes. (shrink)

This book contains a selection of the papers presented at the Logic, Reasoning and Rationality 2010 conference in Ghent. The conference aimed at stimulating the use of formal frameworks to explicate concrete cases of human reasoning, and conversely, to challenge scholars in formal studies by presenting them with interesting new cases of actual reasoning. According to the members of the Wiener Kreis, there was a strong connection between logic, reasoning, and rationality and that human reasoning is rational in so far (...) as it is based on logic. Later, this belief came under attack and logic was deemed inadequate to explicate actual cases of human reasoning. Today, there is a growing interest in reconnecting logic, reasoning and rationality. A central motor for this change was the development of non-classical logics and non-classical formal frameworks. The book contains contributions in various non-classical formal frameworks, case studies that enhance our apprehension of concrete reasoning patterns, and studies of the philosophical implications for our understanding of the notions of rationality. (shrink)

This is a brief, personal retrospective on developments in the treatment of scientific discovery by philosophers, since about 1970.

The way scientific discovery has been conceptualized has changed drastically in the last few decades: its relation to logic, inference, methods, and evolution has been deeply reloaded. The ‘philosophical matrix’ moulded by logical empiricism and analytical tradition has been challenged by the ‘friends of discovery’, who opened up the way to a rational investigation of discovery. This has produced not only new theories of discovery, but also new ways of practicing it in a rational and more systematic way. Ampliative rules, (...) methods, heuristic procedures and even a logic of discovery have been investigated, extracted, reconstructed and refined. The outcome is a ‘scientific discovery revolution’: not only a new way of looking at discovery, but also a construction of tools that can guide us to discover something new. This is a very important contribution of philosophy of science to science, as it puts the former in a position not only to interpret what scientists do, but also to provide and improve tools that they can employ in their activity. (shrink)

In this chapter we address what we call “The-Everybody-Did-It” (TEDI) Syndrome, a symptom for collective negligence. Our main thesis is that the character of scientific communities can be evaluated morally and be found wanting in terms of moral responsibility. Even an epistemically successful scientific community can be morally responsible for consequences that were unforeseen by it and its members and that follow from policy advice given by its individual members. We motivate our account by a critical discussion of a recent (...) proposal by Heather Douglas. We offer three, related criticisms of Douglas’s account. First, she assumes that scientific fields are communicative communities. Second, in a system where the scientific community autonomously sets standards, there is a danger of self-affirming reasoning. Third, she ignores that the character of a scientific community is subject to moral evaluation. We argue that these omissions in Douglas’s theory leave it with no adequate response to TEDI Syndrome. Moreover, we deny that science ought to be characterized by unanimity of belief among its competent practitioners, this leads easily to the vices of close-mindedness and expert-overconfidence. If a scientific community wishes to avoid these vices it should create conditions for an active pluralism when it and its members aspire to the position of rational policy decision-making. (shrink)

This paper lays the groundwork for normative-yet-naturalistic social epistemology. I start by presenting two scenarios for the history of epistemology since Kant, one in which social epistemology is the natural outcome and the other in which it represents a not entirely satisfactory break with classical theories of knowledge. Next I argue that the current trend toward naturalizing epistemology threatens to destroy the distinctiveness of the sociological approach by presuming that it complements standard psychological and historical approaches. I then try to (...) reassert, in Comtean fashion, the epistemologist's credentials in regulating knowledge production. Finally, I consider how social epistemology may have something exciting and relevant to say about contemporary debates in the theory of knowledge. (shrink)

Charles S. Peirce luokitteli 1865 päättelyn lajit deduktioon, induktioon ja hypoteesiin, joista viimeksi mainittua hän luonnehti päättelynä vaikutuksista syihin tai päättelynä selitykseen. Hypoteesi on Peircelle induktion ohella tietoa laajentava päätelmä. 1890-luvun lopun kirjoituksissaan hän alkoi kutsua hypoteettista päättelyä uusilla nimillä ”retroduktio” ja ”abduktio”. Tässä vaiheessa Peirce kuvasi abduktiota tieteellisen päättelyn ensimmäisenä askeleena, mahdollisten arvausten esittämisenä, jonka tulokset on asetettava induktion kautta testeihin. Hänen tunnetuin kaavionsa abduktion loogiselle muodolle on vuodelta 1903: The surprising fact C is observed; But if A were (...) true, C would be a matter of course. Hence, there is reason to think that A is true. Toisin sanoen abduktio päättelee yllättävästä tosiseikasta hypoteettiseen teoriaan, joka selittäisi tämän faktan. Peircen ajatukset tulivat laajemmin tunnetuiksi, kun kuusiosainen Collected Papers ilmestyi 1931-35. Maailmansodan jälkeen hänen ehdotuksiaan on tulkittu kolmessa suunnassa. Hansonin mukaan abduktio on keksimisen logiikkaa. Laudanin mukaan abduktiossa on kyse ohjeesta työskennellä kiinnostavan hypoteesin parissa. Harmanin mukaan abduktio on päättelyä parhaaseen selitykseen. Monet loogikot, tekoälyn tutkijat ja tieteenfilosofit käyttävät termiä ”abduktio” suoraviivaisesti IBE:n synonyyminä, kun taas varovaisemman kannan ottavat mm. Aliseda, Magnani ja Douven. Toisaalta tätä rinnastusta on eri syistä pidetty harhaanjohtavana abduktion todellisen luonteen ja tehtävän perusteella. Myös monet Peirce-tutkijat ovat ottaneet intohimoisesti kantaa asiaan vedoten mestarin monitulkintaisiin kirjoituksiin. Esimerkiksi Minnamaier esittää, että abduktion samaistaminen IBE:n kanssa hämärtäisi Peircen erottelua induktion ja abduktion välillä. Campos argumentoi, että abduktio tulisi rajata selittävien hypoteesien generoimiseen, joten valikointi hypoteesien välillä ei kuulu sen tehtäviin. Gaultierin mukaan skeeman johtopäätös ei ole suositus testata A:n totuutta, vaan selvittää, onko A todellakin mahdollinen selitys C:lle. Sen sijaan Nyrupin mukaan jättää avoimeksi, tukeeko onnistunut selitys hypoteesin totuutta, joten abduktiossa on kyse hypoteesin työstämisestä. Peircen kirjoituksista puolen vuosisadan aikana kuitenkin löytyy aineksia kaikille kolmelle abduktion päätulkinnalle. Abduktio on ainoa menetelmä uusien ideoiden generoimiseksi. Abduktio auttaa tunnistamaan testaamisen arvioisia hypoteeseja. Joissakin tapauksissa, kuten havainnoissa ja historiallisissa päätelmissä, abduktio on ”pakottavaa” tai ”täysin varmaa”, joten sillä voi olla tekemistä myös hypoteesien oikeuttamisen kanssa. Vaikka Peirce päätyi esittämään, ettei abduktiivisiin päätelmiin liity mitään todennäköisyyksiä, hän kuitenkin myöhäisissäkin töissään antoi abduktiolle selkeän loogisen muodon. Lisäksi abduktion ja IBE:n yhteyttä puolustaa käsikirjoitus ”The Logic of Drawing History from Ancient Documents”, jossa Peirce antaa kriteerejä ”abduktiolle eli hypoteesien valinnan prosessille”. Näitä kriteerejä ovat selitysvoima, testattavuus, varovaisuus, laajuus ja yksinkertaisuus. Samantapaisia metodologisia sääntöjä ovat muotoilleet ne tutkijat, jotka ovat kehitelleet eteenpäin IBE:n muotoja. Vastaus otsikon kysymykseen on siis ”kyllä ja ei”. Vaikka Peirce keksi termin ”abduktio”, hänellä ei ole loputonta yksinoikeutta määrätä sen käytöstä. Hän ajatuksensa ovat inspiroivia tavalla, joka voi johtaa abduktion tutkimisessa erilaisiin suuntiin. Näitä linjoja on tarpeetonta oikeaoppisesti pitää toisilleen vastakkaisina. Keksimisen logiikka on kiehtova aihe, mutta samalla tavoin on aihetta analysoida sitä, miten keksittyjen selityshypoteesien paremmuutta voidaan vertailla ja millaisilla ehdoilla voisimme olla oikeutettuja hyväksymään parhaan toistaiseksi löydetyistä selityksistä. Kaikki nämä loogis-metodologiset tutkimuslinjat tekevät omalla tavallaan oikeutta Peircen filosofian suurille oivalluksille. (shrink)

Here are some of the most important discoveries in the history of medicine: blood circulation (1620s), vaccination, (1790s), anesthesia (1840s), germ theory (1860s), X- rays (1895), vitamins (early 1900s), antibiotics (1920s-1930s), insulin (1920s), and oncogenes (1970s). This list is highly varied, as it includes basic medical knowledge such has Harvey’s account of how the heart pumps blood, hypotheses about the causes of disease such as the germ theory, ideas about the treatments of diseases such as antibiotics, and medical instruments such (...) as X-ray machines. The philosophy of medicine should be able to contribute to understanding of the nature of discoveries such as these. The great originators of the field of philosophy of science were all concerned with the nature of scientific discovery, including Francis Bacon (1960), William Whewell (1967), John Stuart Mill (1974), and Charles Peirce (1931-1958). The rise of logical positivism in the 1930s pushed discovery off the philosophical agenda, but the topic was revived through the work of philosophers such as Norwood Russell Hanson (1958), Thomas Nickles (1980), Lindley Darden (1991, 2006), and Nancy Nersessian (1984). Scientific discovery has also become an object of investigations for researchers in the fields of cognitive psychology and artificial intelligence, as seen in the work of Herbert Simon, Pat Langley, and others (Langley et al., 1987; Klahr, 2000). Today, scientific September 14, 2009 discovery is an interdisciplinary topic at the intersection of the philosophy, history, and psychology of science. The aim of this chapter is to identify patterns of discovery that illuminate some of the most important developments in the history of medicine. I have used a variety of sources to identify forty great medical discoveries (Adler, 2004; Friedman and Friedland, 1998; Science Channel, 2006; Strauss and Strauss, 2006).. (shrink)