Elvire, Fifine only exist in the mind of Don Juan; their thoughts are only expressed in his words; their outlines not only continually fade into his, but his thought steals into his presentation of their thought, till it becomes impossible to individualise them.

The form in which Browning wrote the poem, by which he made Don Juan speak for them, makes this want of clearness and sharpness inevitable.

The work is done with a terrible cleverness, but it is wearisome at the last.
The length also might be excused if the subject were a great one or had important issues for mankind.

But, though it has its interest and is human enough, it does not deserve so many thousand lines nor so much elaborate analysis.

A few lyrics or a drama of two acts might say all that is worth saying on the matter.