Review of Coady, C.A. J. Testimony: A Philosophical Study, (Oxford, Oxford University Press, 1992) pp. x, 315. This is a thoughtful and intelligent book about a much-neglected topic. We are all of us reliant on testimony. Were it not for the word of others, we would be pitifully ignorant creatures, since what a person can find out for herself is but a tiny fraction of what we think we know. Without testimony we would not know so much as our passport numbers, our parentage or our dates of birth. Coady deserves full marks for both seeing this and insisting on its importance. For example, testimony poses a problem for Cartesian epistemology which is dominated by the ideal of the autonomous knower, who knows what he knows 'off his own bat'. Unless the autonomous knower can somehow prove, on the basis of his own experience, that testimony is on the whole reliable, all large claims to knowledge of science or history simply collapse. (So much the worse for Cartesian epistemology, says Coady.) But this is not the only issue that Coady considers. There are chapters on Collingwood and historical method, on expert witnesses, on mathematical knowledge, and on psychologists, who (relying on testimony) purport to prove that testimony is unreliable. Though reasonably up-to-date, Coady is no slave to philosophical fashion, but is prepared to enter into dialogue with the past. We meet Russell and Collingwood, Price and Hume, Clifford and Reid as well as Davidson, Dretske and McGinn. (Indeed Reid is the philosopher whose position is the closest to Coady's own and as the standard bearer of 'Scottish fundamentalism, he gets a sympathetic chapter all to himself.) Coady's style is elegant and good-humoured and jargon-free. And at the level of sentences or even paragraphs it is also very clear. ! But I must confess I found the book heavy going, and it is perhaps worth asking why. Maybe Coady's style is too smooth. You are carried along till you find yourself at a conclusion or at the end of a chapter without really knowing how you got there. A few well placed jolts in the form of sub-conclusions vigorously asserted or even reasserted would not have come amiss. Again, Coady could have made the sequence of thought clearer by a larger number of small subsections and and separate headings. I was often unclear as to where we had got to in the argument and felt I had to retrace my steps. But the real problem, I think, is that too often Coady is exploring the issues rather than arguing a case. I felt like a Charles Sturt meandering through trackless philosophical territory. The wide prospects began to pall and I yearned for a few philosophical landmarks. ! 1 ! We start with a trip to Amsterdam which Coady uses to emphasize our reliance on testimony. This poses a problem for the autonomous knower. Unless he can know that testimony is reliable much of what passes for knowledge is mere opinion. Coady mentions four responses puritanism (what is 'known' by testimony simply is not known), reductionism (which professes to establish on other grounds that testimony is reliable), fundamentalism (which insists that testimony simply is a fundamental source of knowledge) and the end-of-epistemology thesis which Coady dismisses as a relapse into mere description. Before going on to consider these responses in detail, Coady develops an account of testimony based on the speech-act of testifying in court. Coady assumes, plausibly enough, that the legal concept of testimony is an elaboration of the concept in common use. `! Though Coady considers three reductonists Hume, Price and Russell it is the chapter on Hume that is crucial. Hume argues that we know testimony is reliable because we have experienced it to be so. But though 'we' collectively may have had experience of the reliability testimony, I only know of this through the testimony of others. Hence experience my experience does not confirm the reliability of testimony. It is only collective experience mediated by testimony that does that. Coady goes on to argue that the reliability of testimony does not admit of empirical proof. For if a conjecture can be confirmed by experience, it must be possible to refute it. Now, suppose that I establish that most reports brought in by witnesses are false. Then it is not clear that they have any title to be regarded as reports. Indeed, Coady seems to be arguing that without a large measure of reliability, it would be impossible for us to learn a language. ! Although Coady is plainly on to something here, these large claims seem to me to be false. Suppose I am (unwittingly) a brain-in-a-vat connected up to a computer-generated virtual reality designed by Doctor Input. Suppose too that there are other brains connected to the same reality. As we 'move' about in the virtual reality we make reports to one another about our discoveries. We are truthful brains and our reports are reliable. That is, if one of my fellow brains (which of course has an illusory body) tells me that a nearby tree has fruit, I can expect that when I 'move' to the relevant 'location', it will seem to me that there is a tree with fruit. But this is all an illusion caused by artful stimulation of my nerve endings, as I find out when Dr Input disconnects me from the virtual reality and wires me up to the real world. If the brains were confined to the vats from birth and fed illusions from their earliest years they could 'speak' and teach a language even though their testimony was systematically false. Of course it would be true of the virtual reality, but the brains (let us suppose) are metaphysical realists and would despise such 'truth' if Dr Input disconnected them and let them in on his little secret. Hence it is possible to learn a 2 language on the basis of false testimony and to discover by empirical means that the testimony is false. ! ! In Chapter 9, Coady tries to adapt his answer to Hume, so as to provide 'some philosophical rationale for [our] reliance on testimony.' Coady considers Davidson's famous claim that we cannot interpret the the utterances of another person (another community, everyone else) without assuming that what they say is substantially correct. Massive error and massive dishonesty are alike conceptual impossibilities. In a long, involved and rambling discussion, Coady pits Davidson's arguments against the criticisms of McGinn. He concludes that for communication to be possible there must be agreement (and veracity) about the evident and the observable, but not about the theoretical and the occult. On the whole, then, testimony about the 'manifest image' of the world can be relied on. When we check on the reports of witnesses, they will tend to square with our own observations. However, this does not mean that they will be true. Think again of the deluded brains. If we enter into their virtual reality by putting on a headset, we can only hope to interpret the 'sounds' they make by assuming that at the phenomenal level, their beliefs are correct and that their utterances truthfully reflect their beliefs. Nevertheless, their beliefs are false. Moreover, on Coady's own showing, people can be wrong (and therefore, dishonest?) about the theoretical and the occult without lapsing into unintelligibility. Imagine a community which habitually lies to outsiders about its religious beliefs. Both the yarns they spin for the benefit of anthropologists and their religious beliefs themselves are massively false, yet anthropologists have no problem understanding the yarns (when they are deceived) or the beliefs (when they penetrate the secrets of the tribe). Thus the conclusions of Coady's transcendental argument are rather weak and equivocal, indeed weaker and more equivocal than he seems to realize. Communication is only possible with creatures which (for the moment) share the same manifest image of the world and are generally honest about the observable. But honest testimony is not necessarily true, as the example of the brains makes clear. As for the theoretical and the occult, massive error and massive deception are both possible. There is no general argument for the reliability of testimony. ! The book concludes with seven chapters on puzzles and applications. These are excellent but I would have enjoyed them more if I had not been worn down by the tortuous discussions in chapters 8 and 9.