Complex sentence: Dimmesdale faces a problem that is both simple and paradoxical: the knowledge of his sin, his inability to disclose it to Puritan society, and his desire for confession.
Split into simpler sentences: Dimmesdale faces a problem that is both simple and paradoxical. Arthur Dimmesdale struggles with the knowledge of his sin, and inability to disclose it to Puritan society and his desire for confession.