Kant’s Madman knocks on doors. He never visits the person he is looking for, but only the friends of that person. He is not very direct in this way. When you open the door, the madman must present himself as homicidal in manner and tone. He also, and this is the hardest part, must conceal an ax so that it is visible to you on the one hand, but makes you believe he is trying to hide it on the other. This takes a lot of practice. His lines are easy. There is only one question to utter. He asks where your friend is. Scary, right? But not really if you have heard about him before. Because even if you give up your friend’s location, the madman won’t go find him. He simply walks from your front step to another house, knocking on a different door, asking the same question to another friend of your friend.