I drew this short comic a while ago after I read the following quote from St. Isaiah the Solitary:
“There is among the passions an anger of the intellect, and this anger is in accordance with nature. Without anger a man cannot attain purity: he has to feel angry with all that is sown in him by the enemy.”
(From “On Guarding the Intellect” which is contained in Volume 1 of the Philokalia and can also be found online by following the link at the bottom of this blog post)