Abstract
The law of fitness (or capacity) to stand trial is, in many jurisdictions, comprised of a mixture of older common law principles and more recent statutory rules. The key to understanding the area is appreciating how the principles drawn from these two sources interact. New Zealand law is used to illustrate this point. It shows how recent statutory provisions may be read as restatements of the older common law principles, or as modifying the procedures through which the older principles are expressed. New Zealand law thus illustrates the typical manner in which the core principle in this field of law, concerning the capacity of an accused person to participate in their trial, is given contemporary effect.