Final answer:
An attorney-in-fact derives powers from a power of attorney, a legal document where the principal grants authority to act on their behalf. The scope is set within the document which can be broad or specific, and the power lasts until the principal's death or revocation.
Step-by-step explanation:
An attorney-in-fact derives his powers from a legal document called a power of attorney (POA). This document is executed by an individual, known as the principal, who authorizes the attorney-in-fact to act on their behalf in specific or general legal matters. The scope of this authority can be narrow or broad, depending on what the principal grants in the POA. The idea behind this is similar to rational-legal authority, where power is based on written rules and regulations, rather than on personal influence.
The attorney-in-fact's power can range from handling financial transactions to making healthcare decisions, depending on the terms set forth in the POA. The authority comes into effect either immediately upon signing the POA or upon the occurrence of a specified event, usually the incapacitation of the principal. This power is inherently tied to the principal's wishes and ceases to be effective on the principal's death or revocation of the POA.
In a broader context, the concept of power and authority can also be discussed in terms of how federal powers are derived and exercised, as in the case with the enumerated powers of Congress and the 'necessary and proper' clause of the Constitution, leading to implied powers. Similarly, concerns about the legitimacy of judicial power arise in discussions about government authority, as seen in the federal judiciary where judges, often not elected, make decisions that can extend or interpret governmental powers.