What do "Mending Wall" by Robert Frost, "Eleanor Rigby" by the Beatles, "Another Brick in the Wall" by Pink Floyd have in common?

The thing "Mending Wall," "Elinor Rigby," and "Another
Brick in the Wall" have in common is the themes of separation, loneliness, isolation,
and dehumanization; this last is implied in the first and explicitly addressed in the
last. A brief examination of each sheds light on the similarities. Though the last line
of Frost's "Mending Wall" seems to advocate a good wall between people, Frost's speaker
has earlier established his opposition and has tried to coax his neighbor into examining
his adage: "Good fences make good friends." Frost’s speaker asks whether “fences making
good neighbors” isn't in fact restricted to land with wandering grazing cows: "Isn't it
/ Where there are cows?"

He speculates that his apple
orchard and the neighbor's pine forest won't bother each other and so don't need to be
walled apart: "He is all pine and I am apple orchard." He concludes by saying of his
neighbor:

He
moves in darkness as it seems to me-- ...
He will not go behind his father's
saying,

This is the speaker's
pronouncement that his neighbor will not, perhaps can not, examine his belief ("go
behind his father's saying") and will continue to impose isolation, separation, and its
resultant loneliness through perpetually mending the wall that nature and man
instinctively tear down:

readability="7">

Something there is that doesn't love a
wall,
That sends the frozen-ground-swell under [ground swell: frost heave that
moves the earth upward] ...
The work of hunters is another
thing

In "Eleanor Rigby," the
Beatles describe the isolation of both Eleanor and Father Mackenzie. Eleanor is dreaming
of the day ("Lives in a dream") that she can have a full and vibrant life that is
connected to other people but can only come close enough to collect traces of others’
lives: "picks up the rice in the church where a / wedding has been." She waits "at the
window," looking her best, for a visitor who never appears ("Who is it for?").
Similarly, Father McKenzie works diligently on his Sunday sermon although no one attends
his church anymore:

readability="5">

writing the words of a sermon that no one will
hear--
No one comes
near.

These two isolated,
lonely, separated souls meet, sadly, at Eleanor's funeral where Father McKenzie performs
her burial rites alone at the graveside.

readability="5">

Nobody came
Father McKenzie wiping the
dirt from his hands as he walks from the
grave

Whereas these two poems
range from speculative examination to lamenting melancholy, "Another Brick in the Wall"
is a brutal poem as well as being about brutality causing isolation, separation, and
loneliness. In addition, the aspect of brutality results in the inclusion of
dehumanization. It is in a restricted sense a child's poem--not suited for children to
read (or hear sung) but about children. Pink Floyd tells of children subjected to hurt
and derision at school administered by teachers themselves brutalized at
home:

teachers
who would hurt the children anyway they could ...
when they got home at
night
[their spouse]
Would thrash them
...!

It is a brutal poem
(ironically administering an emotional thrashing of it's own through vocabulary and
imagery even as it protests against brutality) pleading for a proper perception of the
brutality that causes the separateness, loneliness, and isolation. The final statement
is that such brutality occurs because individuals are wrongly perceived as "just bricks
in the wall," one part of the double metaphor of "wall." "[B]ricks in the wall"
represents the dehumanization the poem protests.