As I exhorted you to stay at Ephesus when I was going into Macedonia, that you might charge certain men not to teach a different doctrine,

 There are the undisciplined (anupotaktoi, G506) . They are the unruly and the insubordinate, those who refuse to obey any authority. They are like soldiers who mutinously disobey the word of command. They are either too proud or too unbridled to accept any control. 