Irrational behaviour is the process of committing an act without the faculty of reason and of mental clarity. In both of Poe’s stories, he clarifies best the capacity of the human mind to observe its own deterioration and the ability of the mind to speak upon its own Thimi 3 destruction without being able to stop its downfall. In the “Tell Tale Heart” the narrator says “I undid the lantern cautiously-oh, so cautiously. I undid it just so much that a single thin ray fell upon the vulture eye. And this I did for seven long nights --every night just at midnight --but I found the eye always closed; and so it was impossible to do the work; for it was not the old man who vexed me, but his Evil Eye.”( The Tell Tale Heart) This initial situation is the narrator’s decision to kill the old man so that the man’s eye will stop looking at the narrator. In “The Black Cat” the man says “ I took from my waistcoat pocket a pen-knife, opened it, grasped the poor beast by the throat, and deliberately cut one of its eyes from the socket!”(The Black Cat) When Plato annoys the narrator,