Epictetus calls out he fake philosophers - the ones who read books and then quote them, but don't actually demonstrate they've thought about and applied what they've read.
The real test of a Stoic is in the acts.
"Let's see how you handle a storm while on board ship. Do you still maintain these distractions when the sails are flapping madly and you're crying out to heaven?" (verse 15)
"If the emperor summons you to answer a charge, do you remember these same distractions when you show up pale and shaking?" (verse 17)
For a true Stoic, virtue is the sole good. If you are a hypocrite, or show cowardice or pretend to be Stoic but are not, you are "dressed up in borrowed colors." (verse 19)
A real Stoic is "someone untroubled with disturbing thoughts about illness, danger, death, exile or loss of reputation." (verse 24)
The soul of a real Stoic is "willing to work with, and never criticize[s], either God or a fellow human being." A real Stoic is "one who will never fail, or have experiences he does not want; who will never give into anger, jealousy or desire[s] to dominate others." A real Stoic is "someone set on becoming a god rather than a man." (verses 26-27)
Epictetus desired to make proof out of his students that "nothing ... is within our power except [the correct use of] impressions." (verse 32)
Showing ... being ... demonstrating ... is Stoic; discussing to learn is good, but then you should get "down to business" and show what you've learned. Otherwise it's all pointless.