Who is Henry Pleyel from Wieland; and Memoirs of Carwin the Biloquist and what is their importance?

Henry Pleyel is a childhood friend of Clara and Theodore Wieland. His outlook lies somewhere between Wieland's ardent beliefs and Carwin's skepticism about supernatural events, but he is willing to consider both rational explanations and supernatural ones. Pleyal trusts his own senses absolutely, and thus, is easily fooled into believing that Clara ruined her reputation through interaction with Carwin. He is unable to reconcile his love for Clara with her apparent disgrace, and thus, he severs all ties with her. Despite Clara's protestations of innocence, Pleyel believes what he has heard with his own ears. Pleyel and Clara later reconcile and marry.