Over at Triablogue, Steve Hays has provided a short and amusing look at the logic behind the flawed argument that goes:
1. Paul says Timothy should keep the things Paul communicated to him orally;
2. Paul did not place any time limit on that command;
3. Therefore, Timothy had to follow them indefinitely; and
3. Therefore, also, we have to keep those oral commands.
Of course, the argument is flawed. But Steve Hays tweaks the argument's nose in a fairly succinct and effective way.
Enjoy! (link) (to which I would simply add: That thou doest, do quickly.)