In classic literature, works fall into one of two categories - tragedy or comedy. In tragic works, you see many common themes.
Some examples -
Simplicity - tragic heroes typically behave predictably and lack flexibility
Preference for the familiar - violating norms brings about the tragic fall, where as in a comedy the hero will see breaking the norm as an opportunity
Uncritical Thinking - tragic heroes tend not to question the accepted order of things
Emotional Engagement - tragic characters often give into their emotions completely and have extreme reactions
Stubborness and Seriousness - tragic heroes have a course and stick to it and they remain serious throughout
Social Isolation - tragedies often stress the individual and their alienation of society
Look at Romeo & Juliet and Macbeth for relevant examples. Romeo & Juliet lack the ability to see other options for themselves. They isolate themselves and are stubborn and one-tracked minded. They absolutely give into their emotions (rather easily) and are unable to think and respond rationally.
Macbeth is certainly stubborn. He isolates himself by killing his friends and their families. He is unable to get past his own greed and amibition and stops at nothing to achieve his goals.
Depending on whether you are looking at Shakespearean or Greek tragedies, you may have serveral added elements. However, the key elements that must be present to validate a tragedy are position of the hero, his tragic flaw, the reversal in the plot, and the recognition of the hero's downfall by the hero himself.
Position means the protagonist is one with great power. He has much to loose. His position is envied or covetted by others. However, the protagonist is one who is adored, respected, and acts out of good intentions. The tragic flaw is that action or characteristic that directs the protagonist to creat an error. These characteristics could be pride, rage, or great sadness from a lost love. When this happens the reversal or irony of the error creates a downfall and great suffering for the protagonist. Finally, within the conclusion, the protagonist becomes aware of his mistake. Unfortunately, in a tragedy, he recognizes this too late to correct what happened.