In "The Cask of Amontillado" suggest any general comments Poe is suggesting about life and the human condition through his themes.

Poe's stories and poems are usually dark and pessimistic,
often invoke the malignant supernatural, demonic possession, and death, and usually show
deterioration of the narrator.

I think Poe sums up his
ideas in “The Imp Of The Perverse”.  The narrator proposes that if we are to understand
humanity, we should study man’s actions.  Then we will find that men often act
irrationally and against their own  best interests.  To the argument that men, after
all, are essentially benevolent to each other, he replies that the same men can be
irresistibly possessed by the demonic “Imp of the Perverse” to do something harmful
which they would not do in their right mind.  For example, we procrastinate doing things
we want to do immediately; standing at the edge of a cliff, we feel the urge to jump
off.

Having finished this exposition, the narrator commits
a murder.  For many years he lives in safety, health, and wealth (which he acquired by
having done the murder).  But at last he is driven by a perverse irresistible urge to
confess his crime.  He writes this story from his death
cell.

Poe portrays man as being surrounded by forces of
evil: if he yields, he is subject to immediate retribution.  The story “A Descent Into
The Maelstrom” expresses this idea metaphorically.  The Maelstrom is a violent whirlpool
in the sea, which can appear without warning and suck an unlucky ship down to its
death.

His poems are well worth reading.  Poems like
“Annabel Lee”, “The Raven”, or “The Conqueror Worm” are as dark and grotesque as his
stories.  Even the melodious “The Bells”, which I think is the most striking of Poe’s
poems, sings of a sequence of bells: first, silver sleigh bells, then golden wedding
bells, then brazen alarm bells, and finally the iron bells of the
death-knell.

See the reference for the text of most of
Poe's works.