Lama Ole’s answer:
Yes, all suffering and difficulties appear from ignorance. We don’t know what causes happiness and suffering, and so we grab the nettles instead of the flowers; we make mistakes all the time. The local religion here [Christianity] has the opinion that anger appears from evil. But Buddha says that its cause is ignorance.
Basic ignorance is mind’s inability to recognize the unity of the observer, what is observed, and the act of observing itself. In other words, subject, object, and action form a totality and condition each other. The unenlightened mind is unable to recognize this unity—just as the eye can see outwardly but cannot see itself.
If we do not recognize this unity, then everything that is happening in the space of mind fragments into an “I” and a “you.” Due to the tension between “I” and “you,” likes and dislikes appear.
More complicated emotions like pride, jealousy, and confusion appear, and one considers them real even though they change constantly. One does one thing, thinks another, and says yet a third thing. This brings results and creates habits, which then come back on oneself. So this is how ignorance becomes the cause of anger.