Instinct is a marvelous thing. It can neither be explained nor ignored.

Christie’s line treats “instinct” as a form of knowledge that operates beneath conscious reasoning. Calling it “marvelous” acknowledges its practical power—especially in situations where evidence is incomplete—while the paired claims (“neither be explained nor ignored”) capture a tension: intuition resists tidy rational accounts, yet it persistently influences judgment and can prove decisive. The quote also hints at Christie’s broader fictional preoccupation with detection and human psychology: motives and truths are often sensed before they are proven. In that sense, instinct becomes an epistemic warning system—unreliable to justify on its own, but dangerous to dismiss.