Many of the rules regarding legal evidence restrict the use of evidence for epistemic reasons – i.e. to help ensure that jurors or judges reach the correct decision – but some rules actually work against the epistemic good. This involves a kind of epistemic paternalism, in the sense that the legal system is controlling what evidence the jurors have access to because it doesn’t trust them to evaluate the evidence correctly. There is a rationale behind such epistemic paternalism, which is that we want our legal system to be such that it protects the rights of the innocent, and hence that there are safeguards in place to try to limit the potential for innocent people to be wrongfully found guilty of crimes.

We looked at two different types of legal system. The first is the adversarial legal system which involves the prosecution and the defence each being charged to mount the strongest opposing case that they can. In contrast, there is also the investigatory legal system where the judge plays a more truth-seeking role. Finally, we examine the nature of legal evidence. It is problematic to base legal judgements on merely statistical evidence, even in the context of civil cases where we are trying to determine liability rather than guilt (and thus where the epistemic thresholds in play are lower). More generally, it is also problematic for a legal system to allow that someone could be convicted purely on the basis of a single piece of evidence, no matter how strong it is, as it would open up the prospect of there being an unduly high number of wrongful convictions. But ensuring that a legal system avoids wrongful convictions can also lead to some types of crime having very low conviction rates, and thus victims of crime not receiving the justice they deserve.