Examine "To Build a Fire" in terms of its theme.

To me, one of the central themes of this unforgettable story of
man against nature is the way that this story reflects the Naturalism of Jack London. Naturalism
is a philosophical idea that presents human beings as subject to natural forces beyond their
control. This idea is clearly one that is central to "To Build a Fire," as the central
protagonist is very over-confident and blasé in his approach to Nature - an over-confidence that
ends up costing him his life. Note how the protagonist is presented as being "without
imagination":

He was a
newcomer in the land, a cheechako, and this was his first winter. The trouble with him was that
he was without imagination. He was quick and alert in the things of life, but only in the things,
and not in the significances. Fifty degrees below zero meant eight-odd degrees of frost. Such
fact impressed him as being cold and uncomfortable, and that was all. It did not lead him to
meditate upon his frailty as a creature of temperature, and upon man's frailty in general, able
to only live within certain narrow limits of heat and cold, and from there on it did not lead him
to the conjectural field of immortality and man's place in the
universe.

This quote, it seems to me,
lies at the heart of the theme London is trying to establish: success in surviving the extremes
of Nature, London seems to be saying, necessarily involves some kind of respect for the raw,
elemental power of Nature and also man's place within Nature. Lack of recognition of man's
"frailty" and "man's place in the universe" leads to foolhardy arrogance which puts our lives at
risk. We underestimate the power of Nature and we overestimate our own position in the natural
order of things, London suggests, at our peril.