A spark neglected makes a mighty fire.

Herrick’s line uses a simple physical image—an unattended spark becoming a conflagration—to warn about the compounding power of small beginnings. The “spark” can be read as a minor fault, temptation, grievance, or danger that seems negligible at first; “neglected” suggests moral or practical failure to check it early. The proverb-like compression fits Herrick’s broader poetic habit of turning everyday observations into ethical counsel. The saying’s enduring appeal lies in its generality: it applies equally to personal habits, social conflicts, and political crises, emphasizing vigilance and timely intervention before problems grow beyond control.