" If it is not right, do not do it; if it is not true, do not say it" 

--Marcus Aurelius--

What this is saying is that if something is not right don't do and if something is not true don't say it. If you do something that's not right then you are doing and choosing whats wrong. If you say something that;s not true then it is wrong because what you are saying is not true and its making you look bad because you are lying about something so therefore you are a lair.  For example if you say something thats not true to someone then they will believe you and then they will go tell other people and so on, then rumors start happening and then at the end they will all blame it on you because you were the one who said it first and the one who started it, then you will end up getting in trouble because you said something that wasn't true. Same thing goes for doing whats not right because if you don't do whats right then you eon't get in trouble because you didn't do in the first place. If you do whats not right then you will end up getting in trouble and having consequences.