All things are the same: familiar in experience, transient in time, sordid in substance. Everything now is as it was in the days of those we have buried.
Mere things stand isolated outside our doors, with no knowledge or report of themselves. What then reports on them? Our directing mind.
Good or ill for the rational social being lies not in feeling but in action: just as also his own virtue or vice shows not in what he feels, but in what he does.
A stone thrown in the air: nothing bad for it on the way down or good for it on the way up.
Penetrate into their directing minds, and you will see what sort of critics you fear - and what poor critics they are of themselves.
All things are in a process of change. You yourself are subject to constant alteration and gradual decay. So too is the whole universe.
You should leave another's wrong where it lies.
In Book 9, chapters 14 to 20, Marcus fires of short and succinct ideas, dealing with the discipline of desire, assent and action.
Change is constant. All that you see today, has similarly happened before. All of it will happen again.
Our mind - our hegemonikon - decides what we agree or disagree with. There is a border - a door, if you will - between external events and our directing mind. We get to look through that door and decide our opinion of what stands outside it. We can let it in or tell it to leave.
We live in a physical world and our actions are confined purely to what we can or cannot do. Our thoughts, directed by our hegemonikon determine our actions and our actions in the physical world are what count.
A stone as been thrown in the air; that is all you can say. You cannot say it is either good our bad. Apply this concept to everything. Don't automatically assume something is good or bad. Simply define at first.
When working with other people (whose minds and actions are out of your control), you may attempt to glance into their mind to see what they see. Close observation will indicate there is nothing for you to fear of them. A similar tactic in modern vernacular is to tell yourself that everyone puts their pants on one leg at a time; everyone defecates; everyone is human. Your fear an anxiety of them truly comes from your directing mind and not from the other person.
Marcus repeats the idea again - change is constant. You, as a physical and mental entity, are subject to constant change and decay.
Lastly, if others commit a wrong act, leave it be. Do not heap on it or add to it.
(see also Citadel p. 43, 258, 271)