According to Wikipedia, the word "athame" (referring to a knife used in ritual magic) is a corruption of "artavus," a quill knife ("a small knife used for sharpening the pens of scribes" -- "cultellus acuendis calamis scriptorii," as found in early editions of the Key of Solomon). Of course the use of such knives in ritual magic has changed over the years and has been subject to fanciful interpretation and outright invention. However, the subtle meaning (as I see it) is that the pen is equivalent to the knife or sword: a tool that cuts between good and evil. Truly writing is a "Scheidekunst," though I see that word not as Novalis sees it (as a perverse artificial separation of philosophia into separate scientific fields that do not inform one another), but as "the art of decision." Surgeons wield the scalpel to access diseased tissue and remove it; critics wield the pen to reveal disorders of thought and excise them.