As mentioned in my previous post on RPG (reasonable and probable grounds) and The Theory of Knowledge, I am in the midst of a MOOC offered by the University of Edinburgh on Philosophy. Last week, the lecture was on “testimony and belief” and specifically discussed the opposing philosophical theories of David Hume and Thomas Reid on the subject.
Much of the intractable disagreement between the two philosophers is really more about religion than it is about philosophy. Thomas Reid, was a deeply religious man and a curate for the first few years of his professional life. David Hume, a staunch critic of religious belief systems, was a religious skeptic. Reid, a proponent of “common sense” and the human ability to sense his or her surroundings, argued that human beings innately believe in the veracity of another person’s testimony. In other words we are genetically disposed or “hard wired” for this belief. This “principle of credulity” as he termed it was connected to our human nature, which is naturally disposed to community, and our desire to trust our senses or feelings in accepting another person’s testimony. Therefore, this divine intuition was an appropriate and logical reason to accept another’s testimony.
Hume, ever the skeptic, required independent evidence that a person’s testimony was likely to be correct. In Hume’s opinion, humans have an incentive to lie when doing so would benefit their own self-interest. Politicians may come to mind as the example. Further, Hume argued, humans are naturally disposed to telling, and enjoying, unsubstantiated stories for the sheer pleasure these stories give themselves and others. The popularity of gossip magazines and the longevity of The National Enquirer can attest to this point.
Immanuel Kant, who was awakened from his “dogmatic slumbers” by Hume’s philosophical theories, also weighed in on the issue. Kant went a step further than Hume by praising “intellectual autonomy” or the ability to be guided, not by another’s testimony, but by an individual’s own understanding and beliefs.
In light of this, how does the law approach testimonial evidence? Does the criminal justice system side with Hume and Kant requiring independent evidence before testimonial evidence will be accepted or does it side with Reid and the God-given nature of people to speak truthfully?
The general rule, it seems, is for Reid – permitting testimony to stand on its own, without requiring corroboration, but in the heightened circumstances of an oath or promise. This binding over of the witness to tell the truth does have a hint of Reid as it invokes the support or, in some ways, corroboration from a higher deity in the case of an oath or a higher power in the case of a promise. However, it is questionable whether Reid himself would deem this precaution necessary.
The criminal justice system relies on testimonial information to support two distinct aspects of a crime. Firstly, testimony is needed as part of the investigation of a crime. Secondly, it is required for at the trial of a crime. Although both aspects view testimony differently, clearly Reid’s principle of credulity applies to both.
During an investigation, the police interview witnesses and possibly the accused to provide the evidence of a crime. Such evidence gathering may precede the officer’s RPG (reasonable and probably grounds) for arrest or it may be gathered after the arrest, when RPG is already present. Although there may be some consideration of the credibility or believability of the testimony given, typically the police will leave the assessment or weighing to the Courts.
Once in the courts, the testimony is received without corroboration or without requiring independent evidence of the testimony. Historically, corroboration was required for a child’s unsworn testimony and for accomplice evidence, but these requirements were abolished or relaxed (Vetrovec warning for accomplice evidence), leaving the trier of fact to determine credibility by assessing the whole of the evidence.
So it appears our laws have applied both Hume and Reid and that the “common sense” approach of Reid has prevailed.