"...no testimony by A to B that p gives B sufficient reason to believe that p unless it is less probable that A is lying or mistaken than p is false. Thus, the more improbable p, the more credible the witness must be for B to be justified in believing that p based on her testimony."(19)The final answer for the author is that Hume had it right; testimony conforming to what is found in "nature" and "convention" is credible. Nature is what we can expect to find, the truth about what we expect to find in human behavior or physical science. Convention is based on the role of the witness. Scientists come together and research to discover truth. Therefore, it is reasonable to believe them.
Root critiques Hume's work in 6 sections, the first three are developmental explaining Hume's terms and reasoning concerning credibility; for example backward-looking reasons, natural and artificial virtue. The fourth section of the article explains convention and the role credibility has in the scientific community, "When one member of a scientific community gives testimony to another she is expected to abide by the norm"(25). Convention, the expectations for the group informs the witness, they don't act as single players but as representatives of the society." The fifth section examines Thomas Reid's viewpoints on testimony. I discuss this in my annotation of an article on St. Augustine's view of testimony. Thomas Reid was a contemporary of Hume and their discourse on testimony is some of rare times philosophy takes up the subject testimony and credibility. Reid felt the witness had credibility unless there was a good reason not to believe him. Reid felt, "...we are naturally disposed to accept testimony of witnesses, and our disoposition is reasonable because witnesses are naturally disposed to tell the truth"(27). Reid called this the principle of credulity and found it sufficient for accepting testimony. Root disagrees and aligns himself with Hume because he finds the important ingredient being convention. The politician, he argues, is not expected to be so truthful because he is not pursuing truth, but instead wants to persuade and get votes. There are different rules governing different witnesses. These conventions hold sway. I see Reid as allowing this by prior examination of the witness for cracks in her credulity. The sixth section brings up modern objections to Hume's argument; these include the nature of truth and trust, Hume's treatment of testimony as evidence based on observation even though witnesses usually make their testimony align with pre-existing truth, and Hume's not accounting for social dimensions that effect real life individual testimonies. The article is hard going, as is much of philosophy, requiring multiple readings. I am surprised the subject of testimony has received such little attention from philosophers when so much of what we "know" is given to us second hand through witnesses, religious, scientific or otherwise. Reading this article informs not only my treatment of Christian testimony, both Apostolic and contemporary, but also my role as a researcher. I remember a discussion in Dr. Bowie's class about falsifying evidence, it had never crossed her mind, but at least one student had thought about it. Without peer-review and integrity within a discipline credibility cannot be maintained. I think this has implications for political activism within scientific inquiry.
