Logic and sermons never convince,
The damp of the night drives deeper into my soul.

The speaker contrasts rational argument (“logic”) and moral exhortation (“sermons”) with the immediacy of bodily, nocturnal experience. The line suggests that persuasion and doctrine fail to reach the deepest layers of feeling, while the physical world—here, the night’s dampness—penetrates inward and shapes the self more powerfully than abstract reasoning. In Whitman’s characteristic mode, the soul is not sealed off from the senses; it is porous, receptive, and altered by contact with nature. The image also hints at loneliness or spiritual unease: night moisture becomes a metaphor for melancholy that seeps in despite intellectual defenses.