Final answer:
Competence is the appropriate standard of substituted judgment for those who were never competent.
Step-by-step explanation:
The most appropriate standard of substituted judgment for those who were never competent is that of competence. In legal terms, competence refers to the mental ability to understand and participate in legal proceedings. It is presumed that a committed patient is competent until proven otherwise. This presumption ensures that individuals who are not competent to stand trial for reasons of illness or insanity are not subjected to punitive measures. The concept of competence also extends to the right to plead guilty or waive legal counsel.