It may be that Hawthorne's failure to take up the cause of the abolitionists is related to his failure to subscribe to any single religious doctrine. This passage suggests that the abolitionist may be as foolish as the man who has placed his faith in a potato. This is not to suggest that Hawthorne was in favor of slavery, but rather that he believed that adamant adherence to any doctrine, however benign, was dangerous. It is useful to compare this idea with his "moralizing" about the father's good intentions in "The Snow Image."
Here were men, whose faith had embodied itself in the form of a potatoe; and others whose long beards had a deep spiritual significance. Here was the abolitionist, brandishing his one idea like an iron flail. In a word, there were a thousand shapes of good and evil, faith and infidelity, wisdom and nonsense,--a most incongruous throng.