Longfellow’s poem ‘A Psalm of Life’ is essentially concerned with the meaning and potential of this life. The speaker slams the pessimists and glorifies this life as ‘real’ in an attempt to challenge the Biblical teaching that says ‘Dust thou art, to dust thou returnest’. In this connection, the poet has compared this world to a vast battlefield and this life to a bivouac (a temporary camp). The troop of soldiers are sent to the camps giving certain duties in a war. Similarly we are sent to this temporary and worldly life with certain duties to perform. Hence the comparison is very apt here.

So this transitory life is a part of a greater arrangement. We have to fulfill the responsibilities that we have been assigned to. We have to win this battle like a hero. This is all about motivating ourselves in performing our duties with a smile.