Bill Marx has a website about his father, that beloved "plug-hatted ragamuffin", Harpo. Thank you, Bill Marx.
Isn't it funny that while Harpo was the silent one, it is his presence in a scene that just completely shatters even that tiniest bit of sense and order? Harpo walks in and suddenly all bets are off. The character he played was, as his son rightly puts it, "a lunatic...a wild man capable of the craziest things imaginable".
Take the immortal lemonade stand scene. No dangerous undercurrents in that one - the currents are all up on the surface. Harpo's rebelliousness, the childlike pleasure he seems to take in destroying things of value (dipping one's feet into a vat of lemonade is just genius) and the funny, absurd, systematic take-down of a man who has done nothing to deserve that troubles that befall him. In other words, the purest comedy: someone else's troubles, viewed from a safe, comfortable distance.
Subversion through comedy is a wonderful thing to watch and who can believe that there once lived a comedian who achieved subversion through silence, scissors, candles and all these other things?