Analysis of Sonnet. Why Did I Laugh Tonight?

Why did I laugh to-night? No voice will tell
No God, no Demon of severe response,
Deigns to reply from Heaven or from Hell
Then to my human heart I turn at once:
Heart! Thou and I are here sad and alone;
I say, why did I laugh? O mortal pain!
O Darkness! Darkness! ever must I moan,
To question Heaven and Hell and Heart in vain.
Why did I laugh? I know this Being's lease,
My fancy to its utmost blisses spreads;
Yet would I on this very midnight cease,
And all the world's gaudy ensigns see in shreds;
Verse, Fame, and Beauty are intense indeed,
But Death intenser -- Death is Life's high meed.