Hamlet's Tragic Flaw

Is Hamlet's distress understandable? Why does he fail to act until too late? Is his inaction due to a tragic flaw?

Until relatively recently, critics tended to assume that the causes of tragic misfortune resided in some moral defect of the protagonist. Aristotle’s term hamartia (derived from “fault,” “failure,” guilt” but literally meaning to “miss the mark”) was often translated as “tragic flaw,” leading critics to seek the chink in the hero’s armour (such as pride or ambition) which leads to his or her downfall. Although the precise meaning of hamartia remains a matter of debate, the notion of the hero’s tragic flaw has inspired a rich tradition of criticism and remains a useful starting point for thinking about character. Some of the
But the psychological point of view is not equivalent to the tragic; and, having once given its due weight to the fact of Hamlet's melancholy, we may freely admit, or rather may be anxious to insist, that this pathological condition would excite but little, if any, tragic interest if it were not the condition of a nature distinguished by that speculative genius on which the Schlegel-Coleridge type of theory lays stress. Such theories misinterpret the connection between that genius and Hamlet's failure, but still it is this connection which gives to his story its peculiar fascination and makes it appear (if the phrase may be allowed) as the symbol of a tragic mystery inherent in human nature. Wherever this mystery touches us, wherever we are forced to feel the wonder and awe of man's godlike 'apprehension' and his 'thoughts that wander through eternity,' and at the same time are forced to see him powerless in his petty sphere of action, and powerless (it would appear) from the very divinity of his thought, we remember Hamlet. And this is the reason why, in the great ideal movement which began towards the close of the eighteenth century, this tragedy acquired a position unique among Shakespeare's dramas, and shared only by Goethe's Faust.
… Now comes the father's death and the mother's second marriage. The long 'repressed' desire to take his father's place in his mother's affection is stimulated to unconscious activity by the sight of some one usurping this place exactly as he himself had once longed to do. … The two recent events, the father's death and the mother's second marriage . . . represented ideas which in Hamlet's unconscious fantasy had for many years been closely associated.

However,

The call of duty to slay his uncle cannot be obeyed because it links itself with the call of his nature to slay his mother's husband, whether this is the first or the second; the latter call is strongly 'repressed,' and therefore necessarily the former also.
“The Oedipus-Complex as An Explanation of Hamlet's Mystery: A Study in Motive,” pp.98-101. http://www.shakespeare-navigators.com/jones/index.html

These are just a few of the most influential early views of Hamlet. Other theories abound, many of which do not impute a flaw to Hamlet. Indeed, it is by no means clear that the causes of tragedy are to be sought in character; Aristotle, for instance, regarded plot as the most important element of drama (followed by character). Consider Baldick’s definition of