This comes from DeLong, but Google tells me it's part of quite old Catholic doctrine.
The Nine Ways of Being an Accessory to Another’s Sin.
1. By counsel.
2. By command.
3. By consent.
4. By provocation.
5. By praise or flattery.
6. By concealment.
7. By partaking.
8. By silence.
9. By defense of the ill done.
See also my post on the two "specialists" who spoke to the Baltimore Sun. They have chosen honor.
