There are many more instructive pairings of words that are useful in understanding the larger picture. for instance the words, violence and violation, also ignorance and ignore. The words disciple and discipline are not positive and negative variations on the root, they are interpreted differently because they have been misused, and the original meaning has become obscure. Think of the meaning of discipline, not in the context of a beating, but in the context of a discipline being a practice. It is something engaged in to better the self. We practice because we want to get better at something. The modern meaning of discipline has been bound together with enforcement. The concepts are separate unless there is force involved, this is apparent in the connection between enforcement and force. Each word has a meaning in context if we lose the meaning it is always instructive to go back to the root and find other words to inform on the nature of the lost meaning.