Poetics (Aristotle) - Aristotle's definition of Tragedy

While defining Tragedy, Aristotle says, “Tragedy is an imitation of an action that is serious, complete, and of a certain magnitude, in the language embellished with each kind of artistic ornament, the several kinds being found in separate parts of the play; in the form of action, not of narrative, through pity and fear effecting the proper purgation- catharsis of these and similar emotions.”
          According to Aristotle, every tragedy is made up of six parts. They are,

Plot, character, thought, diction, and spectacle.
 
(1) Plot:-
Plot, the soul of tragedy, is the most important of six elements. The plot must be complete having unity of action. Aristotle said that plot must be structurally self-contained, with the incident bound together by internal necessity, each action leading inevitably to the next with no outside intervention. There must be good chain of unity of action. The episode or acts succeed one another without probable and necessary sequence. Playwrights should make all scenes which depend on past accident. They have to exclude coincidence from their plot. Plot may be either simple or complex, although complex is better.

(2) Character:-
Character, another important element of tragedy, may be mouthpiece of writer. Every character may have their own contribution to the development of the plot and the purpose of each character must be clear to the audience. Character should have following qualities:
(a) Good or fine
(b) True to Type (Fitness of Character)
(c) True to Life (Realistic)
(d) Consistency (True to Himself)

(3) Thought

Thought is one of the objects of tragedy- the representation of the rational processes of the characters and of the values and ideas articulated in the play.

(4) Diction:-
Diction means Composition of dialogue - Choice of words. In this category artist discusses the stylistic elements of tragedy; is particularly interested in metaphors; but the greatest thing by far is to have a comment of metaphor. It is the mark of genius, for to make good metaphors implies an eye for resembles.

(5) Melody:-
Aristotle said that the music has to blend in the play appropriately. Writer should include the musically expressive quality of something in the play, since some parts of the text of the play are conveyed through the singing of the chorus or of other characters.

(6) Spectacle -         

Spectacle includes all aspects of the tragedy that contribute to its sensory effects: costumes, scenery, the gestures of the actors, the sound of the music and the resonance of the actors' voices. Aristotle ranks spectacle last in importance among the other components of tragedy, remarking that a tragedy does not need to be performed to have its impact on the audience, as it can be read as a text.

        Thus, in 'Poetics' Aristotle has given the ideas about tragedy, its essential elements.