"Obscenity is a cleansing process, whereas pornography only adds to the murk"

In this quote, Henry Miller is making a difference in between profanity and pornography. He recommends that profanity, which is frequently related to offensive or indecent language or habits, can actually serve as a kind of filtration. On the other hand, porn, which is often related to explicit sexual material, only contributes to the confusion and darkness in society. Miller appears to be indicating that obscenity, while it might be shocking or offensive, can ultimately lead to a much deeper understanding and clearness, while pornography just perpetuates the muddled and distorted views of sexuality. This quote highlights the power of language and its capability to either cleanse or corrupt the mind.