Gittin 22 - Who can write the Get?
Everybody can write a Get (divorce document), even people who are normally not considered completely responsible for their actions, such as a deaf-mute or deranged person, or anyone below bat/bar-mitzvah age. It goes without saying that a woman can write a Get, provided that she transfers its ownership to the husband, who can then give "his" Get to her. It is not the writing of the Get that matters, it is the signatures of the witnesses!
That rule sounds a bit strange: can we assume, for example, that a deranged person fulfills the requirement of writing a Get having in his mind that it is for a specific woman? - We have to say that someone who knows watches him and commands him what to do. What about signatures of the witness? - We know that the law is like Rabbi Elazar, that it is the witnesses of giving the Get who matter!? - True, the rule assumes that the signing witnesses will be there for the continuation of the proceedings and will witness the giving of the Get as well, as is usually the case.
Another explanation is that this is a tongue-in-cheek rule. It emphasizes the opinion of Rabbi Meir who says that only the signatures of witnesses matter - according to this, even a deranged person can write a Get.
Who can bring the Get if the husband can't come? Basically anyone, but here the deranged person and the deaf-mute are excluded, because they would have to testify that they saw the Get being written and signed. The Talmud goes into complications of someone who was under bar-mitzvah age when accepted the Get and started the journey, but then grew up, or someone who was normal, became deranged on the way, and then possibly became lucid again.
Art: The witness by John Wells Smith