by John Marshall Harlan

“ There can be no dispute as to the general rules governing the admissibility of the declarations of an agent to affect the principal. The acts of an agent, within the scope of the authority delegated to him, are deemed the acts of the principal. Whatever he does in the lawful exercise of that authority is imputable to the principal, and may be proven without calling the agent as a witness. So, in consequence of the relation between him and the principal, his statement or declaration is under some circumstances regarded as of the nature of original evidence ”

“ But an act done by an agent cannot be varied, qualified, or explained, either by his declarations, which amount to no more than a mere narrative of a past occurrence, or by an isolated conversation held, or an isolated act done, at a later period. ”

“ The practice of admitting in evidence the unsworn statements of witnesses, prepared in advance of trial at the request of one party, and without the knowledge of the other party, should not be encouraged by further departures from the established rules of evidence. ”