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Testimony: a primer
Stud. Hist. Phil. Sci. 33 (2002) 209–217 www.elsevier.com/locate/shpsa
Testimony: a primer Martin Kusch, Peter Lipton Department of History and Philosophy of Science, University of Cambridge, Free School Lane, Cambridge CB2 3RH, UK
You know that you are reading a special issue on testimony because you see these words written on the pages before you. You might come to know that we, the editors, met frequently in preparing this issue by reasoning—that is, drawing inferences— about the likely process of producing a collection of papers. Some of you know of our interest in the topic because you remember one of us talking about it. And you know that putting this issue together has been fun because you have just been told as much by two exceptionally honest and thoroughly competent testifiers. Perception, reasoning, memory, testimony: these are for traditional and mainstream epistemology the four sources of all of our knowledge. The first three are often taken to be non-social capacities; as it is sometimes put, they are ‘onboard’ sources of knowledge for the individual. By contrast, testimony is an epistemic source outside the individual, or between individuals. The history of philosophical theorising about knowledge is of course full of attempts to establish hierarchies between these four sources, and to reduce their number. In such exercises, reasoning and perception have found much favour; memory did well at least in Plato’s dialogue Meno. Only rarely, however, have epistemologists found good things to say about testimony—though testimony has of course always been popular with theologians, historians and lawyers. The philosophical disdain of testimony has several plausible sources. The widespread risk of incompetence and mendacity make the fallibility of testimony obvious, so this is a source of belief that did not appeal to epistemologists looking for certainty (though of course similar things can be said of perception). Testimony has seemed to many not a source of new knowledge but only a vehicle for transmitting knowledge already obtained by other means, and so not of fundamental epistemological interest (though of course similar things can be said of memory). Testimony is also derivative in another way, since to have any effect it must be perceived (though of E-mail addresses: [email protected] (M. Kusch); [email protected] (P. Lipton). 0039-3681/02/$ - see front matter 2002 Elsevier Science Ltd. All rights reserved. PII: S 0 0 3 9 - 3 6 8 1 ( 0 2 ) 0 0 0 0 3 - 1
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course similar things can be said of the reasoning, since arguments require premises). Finally, it has plausibly been suggested that testimony has been virtually ignored in the history of western philosophy because of an underlying presumption of epistemic individualism, according to which whatever it is possible to know, it is possible for an individual to know on her own. Over the past two decades, mainstream (Anglo-American) epistemology has often been taken to task for its alleged excessive and mistaken individualism, that is, for its tendency to ignore social aspects of knowledge. The criticism has come from many quarters, perhaps most vocally from feminist scholars, sociologists of knowledge and philosophers of science. Usually the critics have justified their critique by pointing to the neglect of testimony in mainstream epistemology. That the accusation of individualism should be justified by pointing to the neglect of testimony should not occasion surprise. After all, as mentioned, according to the epistemological tradition itself, testimony is the one and only social source of knowledge. Many epistemologists have taken these criticisms to heart. Indeed, of late testimony has even become something of a fashionable topic in epistemology. Some philosophers such as Tony Coady or Elizabeth Fricker have become well known on the basis of their contributions to this field. And yet renewed interest in testimony is not just characteristic of a particular, younger, generation of philosophers. After all, Burge, Dummett, Goldman, Lehrer, Plantinga and Strawson can also be found amongst recent contributors. In brief, the last decade has seen the publication of a considerable number of competing proposals concerning almost all aspects of testimony. ‘Testimony’ has the ring of a technical epistemological term, but the word has of course long had a much wider currency: historians, theologians and lawyers have always had their own debates over the reliability of reports and witnesses, and in recent decades developmental and social psychologists, as well as sociologists and philosophers of science, have made epistemic interdependence central to their concerns as well. Fortunately, these various strands of concern with knowledge from words have not remained isolated from one another. Indeed, the study of various aspects of testimony seems currently to be emerging as a field of fruitful interdisciplinary contact for all of the above-mentioned fields of study. The papers of our special number document this trend. Given that they all have their own summaries, we shall not re-summarize them here. Instead we shall briefly flag some of the central issues and provide the newcomer to the field with some pointers to the quickly growing literature on testimony, primarily within epistemology. One obvious question about testimony concerns its relative importance in our cognitive economy. How much of what we know depends on the word of others? This is an issue that arises in one form or another in much of the literature on testimony, and usually the answer that emerges is that our dependence is very great. (This point has been brought out with particular force by Tony Coady.) This is in retrospect not surprising, since for example the reach in space and time of what you have observed for yourself is miniscule as compared with the range covered by your beliefs about the way things were before you were born, will be after you die and are elsewhere while you are alive; and it is highly implausible to suppose that the bulk of those
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beliefs are the result of inferences from premises exclusively about what you have yourself observed. Very little indeed of what you know you worked out entirely on your own. But the extent of our dependence on the word of others does not by itself settle the question of the depth of that dependence. Is testimony merely a convenient source of knowledge, given the shortness of life and the awkwardness of trying to be in two places at the same time, or is there some deeper reason why the idea of a feral knower is incoherent? One route to the thought that knowledge is essentially social is by way of the social aspects of language. If at least much of our knowledge is only possible in a linguistic medium, and language is essentially social, then so is knowledge. Another related route is by way of questioning whether the division between the four sources of knowledge with which we began this essay is really adequate. In particular, we may on reflection have to give up the dividing line between testimony and the ‘nonsocial’ sources of knowledge. Is there not evidence enough (from, for example, psychology, history, philosophy and sociology) that perception, reasoning and memory are social in fundamental ways too? If, however, we ‘deconstruct’ individualistic assumptions around all sources of knowledge, this may lead to a re-conceptualisation of the relationship between the four sources, a re-drawing and softening of their respective boundaries, and an appreciation of the ineliminability of social aspects of knowledge. However wide and deep our dependence on testimony, our acceptance of the world of others cannot be completely undiscriminating. We cannot believe everything we are told. This raises another central issue in the epistemology of testimony: how do we decide which testimony to accept? Are the principles of selection here reducible to general principles of reasoning, or are they in some respects sui generis? A particular aspect of this question that especially interests the two of us is how we should compare human informants and instruments in regard to testimony. Is learning from others a special case of learning from instruments, in that, for example, the tracking of track records (as one of us once put it) is similarly applicable in both cases? Or is the assimilation of humans to instruments a violation of thinking of testifiers in terms of the ‘participant stance’? (See Section 7 below for references to this Strawsonian notion.) Alternatively, should we go the other way, and assimilate computers and machines to humans? Should we extend the participant stance to machines as well? Another topic in the epistemology of testimony that particularly interests us concerns the acquisition of non-propositional knowledge, skill or know-how. How does this form of learning differ from the standard cases considered in the literature on testimony? Testimony may of course contribute to learning how, but there is also the case of imitation, where both the input and the output of the process may be non-propositional. At this point epistemology could make fruitful contact with work done in the sociology of knowledge and the philosophy of science. See, for example, Collins (1985, 1990); Collins and Kusch (1998); Polanyi (1958).
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Bibliographical essay 1. Starting points Those are a few of our favourite things, in the epistemology of testimony. For readers wishing to begin to explore the blossoming literature on testimony, we suggest alongside the volume in your hands Coady (1992, 1997); Matilal and Chakrabarti (1994); Quine and Ullian (1970); Sosa (1992). 2. Classic texts The two most important classic discussions are in Hume’s and Reid’s ‘inquiries’ (Hume, 1966; Reid, 1970). An important modern classic is Collingwood’s discussion of testimony in history (Collingwood, 1970). Recent discussions also refer often to Price (1969) and Russell (1927, 1948). Fine critical expositions and discussions of all these authors can be found in Coady (1992). The most detailed exposition and critical discussion of Hume on miracles is in Earman (2000). A detailed review of the history of classic philosophical discussions about testimony (especially in England during the sixteenth and seventeenth centuries) can be found in Shapin (1994). 3. Testimony and related categories in Continental and non-Western philosophy In the Continental tradition, the category of ‘testimony’ has not been central. Nevertheless, many of the central debates in and around hermeneutics touch upon similar concerns. See especially Gadamer (1991). For discussions of testimony in African and Indian philosophy, see Hallen and Olubi Sodipo (1997) and the relevant papers in Matilal and Chakrabarti (1994). 4. The limits of testimony Epistemologists disagree over the scope and usefulness of the category of testimony. Some conceive of testimony narrowly as legal testimony, that is, as the testimony delivered by a witness in a court of law. Other epistemologists treat testimony as a covering term for all phenomena of our so-called ‘epistemic interdependence’. In between these two extremes one can find a position that equates knowledge by testimony with knowledge gained from others’ present- or past-tense indicative say-so. A good discussion of the scope of testimony is Part I of Coady (1992). Criticisms of epistemologists’ emphasis on testimony as a key category can be found in Popper (1965) and Fuller (1996). The inflation of the term is lamented in Quinton (1982). Locke (1975) famously dismissed testimony. Epistemologists differ in their answer to the question of whether testimony can ever be a generative source of knowledge. Individualists answer ‘no’: testimony, they insist, can only pass on, or transmit, items of knowledge from one individual
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to another, but it can never create new items of knowledge. Individualists think that only the onboard sources of perception and reasoning can be truly generative of new items of knowledge. The individualists’ opponents—let’s call them ‘communitarians’—disagree; for them testimony is usually generative. The view that testimony is not a generative source of knowledge is maintained in Audi (1997, 1998); Dummett (1994); Fricker (1987); Plantinga (1993). For the ‘communitarian’ view see Section 7 below. 5. Inferentialism—pro and contra One of the most central contemporary debates in the epistemology of testimony concerns the question of whether our adoption of beliefs based on testimony is, or should be, either ‘direct’ or ‘inferential’. The problem is usually introduced in the context of a comparison with perception. Under normal circumstances, seeing leads directly to believing. In the case of perceptual beliefs we usually find ourselves forming beliefs directly and only rarely inferentially. And we are convinced that our practice is defensible. But what about testimonial beliefs? Do you believe that Marina Frasca Spada and Nick Jardine greatly helped us in editing this issue upon reading our claim to that effect; or do you believe it only after securing additional premises concerning our honesty and competence in speaking about our colleagues? If you think that belief-formation in the case of testimony does, or should, always involve inferences, then you are an ‘inferentialist’ about testimony. The best general exposition and defence of inferentialism can be found in the papers of Fricker (1987, 1994, 1995). Inferentialism is discussed in Lipton (1998). Direct criticisms of Fricker can be found in Bhattacharyya (1994); Chakrabarti (1994); Welbourne (1994). The anti-inferentialist position is advocated in Coady (1997); Austin (1979); Dummett (1994); McDowell (1998). McDowell’s treatment of the topic builds on some important comments on testimony by Evans (1982) and Strawson (1994). 6. The global justification of testimony Concern with ‘local justification’ of testimony is the concern with justifying why a particular report or witness should be trusted. ‘Global justification’ is after bigger game. The goal here is not to find out whether this or that specific testifier should be trusted; the aim is rather to determine whether it is rational ‘in principle’—that is, prior to, or independently of, receiving specific testimony—to rely on the words of others. The two main attempts to provide a global justification go back to the days of David Hume and Thomas Reid: Hume advocated a ‘reductive’ global justification; Reid a ‘fundamentalist’ one. Put in a nutshell, the reductivist seeks a justification of testimony in terms of deliveries of the other three ‘onboard’ sources of knowledge. The fundamentalist sees testimony as irreducible in that sense, but believes that general trust in testimony can nevertheless be defended in some other way. The latter is denied by the ‘quietist’ about global justification. Hume presents his reductionism in Hume (1966). The most detailed criticism is in
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Coady (1992, 1997); Lipton (1998); Plantinga (1993); Quinton (1982); Ross (1986); Schmitt (1994, 1999); Stevenson (1993). Quietism is defended in Kusch (2002). This brand of quietism is influenced by McDowell (1994) and Williams (1991, 1999), who argue for quietism in other domains of epistemology. The classic defence of fundamentalism is Reid (1970). Good discussions of Reid’s fundamentalism are Coady (1997); Lehrer and Smith (1985) and Lehrer (1989). A closely related form of fundamentalism can be found in Plantinga (1993). Other forms of fundamentalism include Coady (1997); Lehrer (1997) and Gibbard (1990). Kornblith’s (1987) naturalistic defence of trust in testimony is also a form of nonreductionism. A recently much discussed original form of fundamentalism has been proposed by Burge (1993). See also Burge (1997, 1998). For discussion, see Christensen and Kornblith (1997); Bezuidenhout (1998); Faulkner (2000); Edwards (2000). Coady’s brand of fundamentalism relies centrally on anti-sceptical arguments by Davidson (1990). For discussion, see Plantinga (1993); Haack (1993); Foley and Fumerton (1985). 7. Testimony in communitarian epistemology John Hardwig, Michael Welbourne and Martin Kusch have proposed ‘communitarian epistemologies of testimony’. Communitarian epistemology stresses that testimony is a generative source of knowledge. Hardwig’s arguments focus on the role of testimony in science. He has developed his position in two papers (Hardwig, 1985, 1991). Hardwig’s views are critically discussed in Adler (1994); Blais (1985, 1990); Woods (1989); Webb (1993). For contemporary historical, sociological and philosophical work on testimony in the sciences, related to Hardwig’s suggestions, see Galison (1997); Kitcher (1993); Knorr Cetina (1995, 1999); MacKenzie (1999); Shapin and Schaffer (1985); Shapin (1994). Welbourne develops his position most systematically in Welbourne (1993). See also Welbourne (1994). A testimony-centred view of knowledge is also developed in Craig (1990). Welbourne’s ideas resemble work on trust and participant stance by Baier, Holton and Strawson (Holton, 1994; Strawson, 1974; Baier, 1986). An interesting further development of Welbourne’s position is Code (1987). For Kusch’s position, see his contribution to this special issue and Kusch (2002). 8. Testimony and Bayesianism The tools of Bayesianism have been used for analysing testimony acceptance. This is a fairly technical area, but two books are useful starting points: Earman (2000) and Goldman (1999).
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9. Testimony, machines and computers It is controversial amongst students of testimony whether machines (such as computers) can be treated as testifiers. In social studies of science, this question is linked to arguments over the ‘moral’ standing of machines in general. For different positions on this score, see for example Latour (1993); Haraway (1991); Collins; Kusch (1998). For a fascinating anthropological case study of the interaction between human and machine testimony, see Hutchins (1995). Burge’s (1998) paper is both a useful guide to discussions on computers as testifiers and an original contribution to the topic. The role of computer proof is also discussed in MacKenzie (1999). 10. Testimony and political philosophy For an interesting attempt to combine political philosophy and the epistemology of testimony, see Fricker (1998). A feminist theory of testimony has been developed by Code (1999).
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Testimony: a primer Martin Kusch, Peter Lipton Department of History and Philosophy of Science, University of Cambridge, Free School Lane, Cambridge CB2 3RH, UK
You know that you are reading a special issue on testimony because you see these words written on the pages before you. You might come to know that we, the editors, met frequently in preparing this issue by reasoning—that is, drawing inferences— about the likely process of producing a collection of papers. Some of you know of our interest in the topic because you remember one of us talking about it. And you know that putting this issue together has been fun because you have just been told as much by two exceptionally honest and thoroughly competent testifiers. Perception, reasoning, memory, testimony: these are for traditional and mainstream epistemology the four sources of all of our knowledge. The first three are often taken to be non-social capacities; as it is sometimes put, they are ‘onboard’ sources of knowledge for the individual. By contrast, testimony is an epistemic source outside the individual, or between individuals. The history of philosophical theorising about knowledge is of course full of attempts to establish hierarchies between these four sources, and to reduce their number. In such exercises, reasoning and perception have found much favour; memory did well at least in Plato’s dialogue Meno. Only rarely, however, have epistemologists found good things to say about testimony—though testimony has of course always been popular with theologians, historians and lawyers. The philosophical disdain of testimony has several plausible sources. The widespread risk of incompetence and mendacity make the fallibility of testimony obvious, so this is a source of belief that did not appeal to epistemologists looking for certainty (though of course similar things can be said of perception). Testimony has seemed to many not a source of new knowledge but only a vehicle for transmitting knowledge already obtained by other means, and so not of fundamental epistemological interest (though of course similar things can be said of memory). Testimony is also derivative in another way, since to have any effect it must be perceived (though of E-mail addresses: [email protected] (M. Kusch); [email protected] (P. Lipton). 0039-3681/02/$ - see front matter 2002 Elsevier Science Ltd. All rights reserved. PII: S 0 0 3 9 - 3 6 8 1 ( 0 2 ) 0 0 0 0 3 - 1
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course similar things can be said of the reasoning, since arguments require premises). Finally, it has plausibly been suggested that testimony has been virtually ignored in the history of western philosophy because of an underlying presumption of epistemic individualism, according to which whatever it is possible to know, it is possible for an individual to know on her own. Over the past two decades, mainstream (Anglo-American) epistemology has often been taken to task for its alleged excessive and mistaken individualism, that is, for its tendency to ignore social aspects of knowledge. The criticism has come from many quarters, perhaps most vocally from feminist scholars, sociologists of knowledge and philosophers of science. Usually the critics have justified their critique by pointing to the neglect of testimony in mainstream epistemology. That the accusation of individualism should be justified by pointing to the neglect of testimony should not occasion surprise. After all, as mentioned, according to the epistemological tradition itself, testimony is the one and only social source of knowledge. Many epistemologists have taken these criticisms to heart. Indeed, of late testimony has even become something of a fashionable topic in epistemology. Some philosophers such as Tony Coady or Elizabeth Fricker have become well known on the basis of their contributions to this field. And yet renewed interest in testimony is not just characteristic of a particular, younger, generation of philosophers. After all, Burge, Dummett, Goldman, Lehrer, Plantinga and Strawson can also be found amongst recent contributors. In brief, the last decade has seen the publication of a considerable number of competing proposals concerning almost all aspects of testimony. ‘Testimony’ has the ring of a technical epistemological term, but the word has of course long had a much wider currency: historians, theologians and lawyers have always had their own debates over the reliability of reports and witnesses, and in recent decades developmental and social psychologists, as well as sociologists and philosophers of science, have made epistemic interdependence central to their concerns as well. Fortunately, these various strands of concern with knowledge from words have not remained isolated from one another. Indeed, the study of various aspects of testimony seems currently to be emerging as a field of fruitful interdisciplinary contact for all of the above-mentioned fields of study. The papers of our special number document this trend. Given that they all have their own summaries, we shall not re-summarize them here. Instead we shall briefly flag some of the central issues and provide the newcomer to the field with some pointers to the quickly growing literature on testimony, primarily within epistemology. One obvious question about testimony concerns its relative importance in our cognitive economy. How much of what we know depends on the word of others? This is an issue that arises in one form or another in much of the literature on testimony, and usually the answer that emerges is that our dependence is very great. (This point has been brought out with particular force by Tony Coady.) This is in retrospect not surprising, since for example the reach in space and time of what you have observed for yourself is miniscule as compared with the range covered by your beliefs about the way things were before you were born, will be after you die and are elsewhere while you are alive; and it is highly implausible to suppose that the bulk of those
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beliefs are the result of inferences from premises exclusively about what you have yourself observed. Very little indeed of what you know you worked out entirely on your own. But the extent of our dependence on the word of others does not by itself settle the question of the depth of that dependence. Is testimony merely a convenient source of knowledge, given the shortness of life and the awkwardness of trying to be in two places at the same time, or is there some deeper reason why the idea of a feral knower is incoherent? One route to the thought that knowledge is essentially social is by way of the social aspects of language. If at least much of our knowledge is only possible in a linguistic medium, and language is essentially social, then so is knowledge. Another related route is by way of questioning whether the division between the four sources of knowledge with which we began this essay is really adequate. In particular, we may on reflection have to give up the dividing line between testimony and the ‘nonsocial’ sources of knowledge. Is there not evidence enough (from, for example, psychology, history, philosophy and sociology) that perception, reasoning and memory are social in fundamental ways too? If, however, we ‘deconstruct’ individualistic assumptions around all sources of knowledge, this may lead to a re-conceptualisation of the relationship between the four sources, a re-drawing and softening of their respective boundaries, and an appreciation of the ineliminability of social aspects of knowledge. However wide and deep our dependence on testimony, our acceptance of the world of others cannot be completely undiscriminating. We cannot believe everything we are told. This raises another central issue in the epistemology of testimony: how do we decide which testimony to accept? Are the principles of selection here reducible to general principles of reasoning, or are they in some respects sui generis? A particular aspect of this question that especially interests the two of us is how we should compare human informants and instruments in regard to testimony. Is learning from others a special case of learning from instruments, in that, for example, the tracking of track records (as one of us once put it) is similarly applicable in both cases? Or is the assimilation of humans to instruments a violation of thinking of testifiers in terms of the ‘participant stance’? (See Section 7 below for references to this Strawsonian notion.) Alternatively, should we go the other way, and assimilate computers and machines to humans? Should we extend the participant stance to machines as well? Another topic in the epistemology of testimony that particularly interests us concerns the acquisition of non-propositional knowledge, skill or know-how. How does this form of learning differ from the standard cases considered in the literature on testimony? Testimony may of course contribute to learning how, but there is also the case of imitation, where both the input and the output of the process may be non-propositional. At this point epistemology could make fruitful contact with work done in the sociology of knowledge and the philosophy of science. See, for example, Collins (1985, 1990); Collins and Kusch (1998); Polanyi (1958).
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Bibliographical essay 1. Starting points Those are a few of our favourite things, in the epistemology of testimony. For readers wishing to begin to explore the blossoming literature on testimony, we suggest alongside the volume in your hands Coady (1992, 1997); Matilal and Chakrabarti (1994); Quine and Ullian (1970); Sosa (1992). 2. Classic texts The two most important classic discussions are in Hume’s and Reid’s ‘inquiries’ (Hume, 1966; Reid, 1970). An important modern classic is Collingwood’s discussion of testimony in history (Collingwood, 1970). Recent discussions also refer often to Price (1969) and Russell (1927, 1948). Fine critical expositions and discussions of all these authors can be found in Coady (1992). The most detailed exposition and critical discussion of Hume on miracles is in Earman (2000). A detailed review of the history of classic philosophical discussions about testimony (especially in England during the sixteenth and seventeenth centuries) can be found in Shapin (1994). 3. Testimony and related categories in Continental and non-Western philosophy In the Continental tradition, the category of ‘testimony’ has not been central. Nevertheless, many of the central debates in and around hermeneutics touch upon similar concerns. See especially Gadamer (1991). For discussions of testimony in African and Indian philosophy, see Hallen and Olubi Sodipo (1997) and the relevant papers in Matilal and Chakrabarti (1994). 4. The limits of testimony Epistemologists disagree over the scope and usefulness of the category of testimony. Some conceive of testimony narrowly as legal testimony, that is, as the testimony delivered by a witness in a court of law. Other epistemologists treat testimony as a covering term for all phenomena of our so-called ‘epistemic interdependence’. In between these two extremes one can find a position that equates knowledge by testimony with knowledge gained from others’ present- or past-tense indicative say-so. A good discussion of the scope of testimony is Part I of Coady (1992). Criticisms of epistemologists’ emphasis on testimony as a key category can be found in Popper (1965) and Fuller (1996). The inflation of the term is lamented in Quinton (1982). Locke (1975) famously dismissed testimony. Epistemologists differ in their answer to the question of whether testimony can ever be a generative source of knowledge. Individualists answer ‘no’: testimony, they insist, can only pass on, or transmit, items of knowledge from one individual
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to another, but it can never create new items of knowledge. Individualists think that only the onboard sources of perception and reasoning can be truly generative of new items of knowledge. The individualists’ opponents—let’s call them ‘communitarians’—disagree; for them testimony is usually generative. The view that testimony is not a generative source of knowledge is maintained in Audi (1997, 1998); Dummett (1994); Fricker (1987); Plantinga (1993). For the ‘communitarian’ view see Section 7 below. 5. Inferentialism—pro and contra One of the most central contemporary debates in the epistemology of testimony concerns the question of whether our adoption of beliefs based on testimony is, or should be, either ‘direct’ or ‘inferential’. The problem is usually introduced in the context of a comparison with perception. Under normal circumstances, seeing leads directly to believing. In the case of perceptual beliefs we usually find ourselves forming beliefs directly and only rarely inferentially. And we are convinced that our practice is defensible. But what about testimonial beliefs? Do you believe that Marina Frasca Spada and Nick Jardine greatly helped us in editing this issue upon reading our claim to that effect; or do you believe it only after securing additional premises concerning our honesty and competence in speaking about our colleagues? If you think that belief-formation in the case of testimony does, or should, always involve inferences, then you are an ‘inferentialist’ about testimony. The best general exposition and defence of inferentialism can be found in the papers of Fricker (1987, 1994, 1995). Inferentialism is discussed in Lipton (1998). Direct criticisms of Fricker can be found in Bhattacharyya (1994); Chakrabarti (1994); Welbourne (1994). The anti-inferentialist position is advocated in Coady (1997); Austin (1979); Dummett (1994); McDowell (1998). McDowell’s treatment of the topic builds on some important comments on testimony by Evans (1982) and Strawson (1994). 6. The global justification of testimony Concern with ‘local justification’ of testimony is the concern with justifying why a particular report or witness should be trusted. ‘Global justification’ is after bigger game. The goal here is not to find out whether this or that specific testifier should be trusted; the aim is rather to determine whether it is rational ‘in principle’—that is, prior to, or independently of, receiving specific testimony—to rely on the words of others. The two main attempts to provide a global justification go back to the days of David Hume and Thomas Reid: Hume advocated a ‘reductive’ global justification; Reid a ‘fundamentalist’ one. Put in a nutshell, the reductivist seeks a justification of testimony in terms of deliveries of the other three ‘onboard’ sources of knowledge. The fundamentalist sees testimony as irreducible in that sense, but believes that general trust in testimony can nevertheless be defended in some other way. The latter is denied by the ‘quietist’ about global justification. Hume presents his reductionism in Hume (1966). The most detailed criticism is in
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Coady (1992, 1997); Lipton (1998); Plantinga (1993); Quinton (1982); Ross (1986); Schmitt (1994, 1999); Stevenson (1993). Quietism is defended in Kusch (2002). This brand of quietism is influenced by McDowell (1994) and Williams (1991, 1999), who argue for quietism in other domains of epistemology. The classic defence of fundamentalism is Reid (1970). Good discussions of Reid’s fundamentalism are Coady (1997); Lehrer and Smith (1985) and Lehrer (1989). A closely related form of fundamentalism can be found in Plantinga (1993). Other forms of fundamentalism include Coady (1997); Lehrer (1997) and Gibbard (1990). Kornblith’s (1987) naturalistic defence of trust in testimony is also a form of nonreductionism. A recently much discussed original form of fundamentalism has been proposed by Burge (1993). See also Burge (1997, 1998). For discussion, see Christensen and Kornblith (1997); Bezuidenhout (1998); Faulkner (2000); Edwards (2000). Coady’s brand of fundamentalism relies centrally on anti-sceptical arguments by Davidson (1990). For discussion, see Plantinga (1993); Haack (1993); Foley and Fumerton (1985). 7. Testimony in communitarian epistemology John Hardwig, Michael Welbourne and Martin Kusch have proposed ‘communitarian epistemologies of testimony’. Communitarian epistemology stresses that testimony is a generative source of knowledge. Hardwig’s arguments focus on the role of testimony in science. He has developed his position in two papers (Hardwig, 1985, 1991). Hardwig’s views are critically discussed in Adler (1994); Blais (1985, 1990); Woods (1989); Webb (1993). For contemporary historical, sociological and philosophical work on testimony in the sciences, related to Hardwig’s suggestions, see Galison (1997); Kitcher (1993); Knorr Cetina (1995, 1999); MacKenzie (1999); Shapin and Schaffer (1985); Shapin (1994). Welbourne develops his position most systematically in Welbourne (1993). See also Welbourne (1994). A testimony-centred view of knowledge is also developed in Craig (1990). Welbourne’s ideas resemble work on trust and participant stance by Baier, Holton and Strawson (Holton, 1994; Strawson, 1974; Baier, 1986). An interesting further development of Welbourne’s position is Code (1987). For Kusch’s position, see his contribution to this special issue and Kusch (2002). 8. Testimony and Bayesianism The tools of Bayesianism have been used for analysing testimony acceptance. This is a fairly technical area, but two books are useful starting points: Earman (2000) and Goldman (1999).
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9. Testimony, machines and computers It is controversial amongst students of testimony whether machines (such as computers) can be treated as testifiers. In social studies of science, this question is linked to arguments over the ‘moral’ standing of machines in general. For different positions on this score, see for example Latour (1993); Haraway (1991); Collins; Kusch (1998). For a fascinating anthropological case study of the interaction between human and machine testimony, see Hutchins (1995). Burge’s (1998) paper is both a useful guide to discussions on computers as testifiers and an original contribution to the topic. The role of computer proof is also discussed in MacKenzie (1999). 10. Testimony and political philosophy For an interesting attempt to combine political philosophy and the epistemology of testimony, see Fricker (1998). A feminist theory of testimony has been developed by Code (1999).
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