In "Pity this busy monster, manukind," what does the speaker mean when he says that "progress is a comfortable disease"?How does it relate to...

This is an excellent question! Like many works of the
"modernist" period in American literature (which covered roughly the first half of the
twentieth century), Cummings' poem satirizes the modern obsession with material
"progress." Many writers at the time believed that modern people were so obsessed with
making money and accumulating wealth that they had abandoned an interest in more lofty,
more idealistic values.

It seems signifcant that the first
adjective used in the poem is "busy" (1). This word implies the modern emphasis on work
of all kinds, including physical labor in industrial settings but also including the
work of appropriately named
businessmen.

Therefore, by asserting
that "Progress is a comfortable disease," the speaker of Cummings' poem seems to imply
that an obsession with material progress is a kind of spiritual or psychological
sickness.  It can make people financially "comfortable"; it can seem "comfortable" to
those (especially the wealthy) who benefit from it; but ultimately it can also be
somewhat soul-destroying.