Many ordinary people are forced to make hard choices every day. This is especially true of jurors in the American justice system. Jurors preside over a defendant’s fate during a trial. They consider the evidence and then decide between two competing hypotheses:
The two hypotheses are not weighted equally: the defendant is presumed to be innocent until proven guilty. Thus, the jurors assume that the innocence hypothesis is true. They can only reject the innocence hypothesis if the prosecution’s evidence is convincing. Yet the evidence is rarely 100% conclusive, and some doubt of the defendant’s guilt remains. That doubt is factored into the legal process. The jury is instructed to accept the innocence hypothesis if there is “reasonable doubt” of the defendant’s guilt. They can only reject the innocence hypothesis if the defendant appears guilty “beyond a reasonable doubt.”