A nation that forgets its past can function no better than an individual with amnesia.

McCullough’s line frames historical memory as a prerequisite for competent civic life. By likening a nation to an amnesiac individual, he suggests that collective identity, judgment, and continuity depend on remembering prior experience—successes, failures, and hard-won lessons. The comparison also implies vulnerability: just as amnesia leaves a person easily disoriented and manipulated, historical ignorance can leave a public susceptible to simplistic narratives, repeated mistakes, and weakened democratic deliberation. In this view, studying history is not antiquarianism but a practical tool for self-government, helping citizens and leaders orient decisions within a longer arc of cause and consequence.