What does the brook represent in "The Scarlet Letter"?

I'd agree with husband and lover, but ever more plainly --- the world of men and women. Its the strongest running theme. For a women to live on her own, to teach in her own voice... this is a time when women where to be the silent wards of men. Has this changed much? For the most part. Uhem, but anyhow... The worlds of men and women, and the pure and naturally thing that can draw them together: friendship and lust.