The poem states the mood in the first line: "Mary sat musing..." The poem is not an intense examination of anything, but rather a gentle recollection of a gentle man who has come back to the only family he has even know, come home to die.
Mary pushes Warren out the door so that she can talk to him without Silas' hearing; this may not be necessary because he may be already have died, but it is necessary for us to watch the gentle Mary let Warren do his manly rant, and to watch Warren's essentially goodness bubble through his initial reaction. As the poem meanders on, Warren recalls the past times with Silas, often times in terms of nature images: finding water with a hazel prong, bundling hay exactly, working in the fields all suggest a naturalness that will end in the most natural of endings for Silas ---- death.
It leads to Warren's realization:
Poor Silas, so concerned for other folk,
And nothing to look backward to with pride,
And nothing to look forward to with hope,
So now and never any different.”
After a brief pause where Mary "catches" the moon in her lap, where she pulls on the morning glory strings, more images of nature, one of the central discussons come about the meaning of "home," one of the warmest words in the poem. Their two "definitions" come in a special order with Warren's the most "hostile" coming first, and Mary's more understanding following:
“Home is the place where, when you have to go there,
They have to take you in.”
“I should have called it
Something you somehow haven’t to deserve.”
Love, clearly the unspoken in the poem, is defined in terms of home, not the place ruled by obligation ("have to go ... have to take you in), but it terms of love ("haven't to deserve).
Through careful use of gentle nature language and images, Frost presents an elegant statement about the dignity of even the lowliest among us, and the wonderful compassion of two ordinary individuals who provide a "home" where this wounded soul can come home and die with dignity.