Henry Wadsworth Longfellow’s poem “A Psalm of Life” has the subtitle “What The Heart Of The Young Man Said To The Psalmist.” This subtitle suggests that this “young man” whose “heart” is speaking is not necessarily the poet himself.

The youth, energy, and passion of the speaker are made apparent by the kind of advice he offers. He advocates a life of heroism and action in which a person takes risks, lives in the present, and does not worry about the past. Nevertheless, he also urges his audience or reader to anticipate the effect that their actions will have on a future stranger.

Using a metaphor comparing life to a battle, the speaker advocates heroism, implying that this means leading rather than following:

Be not like dumb, driven cattle!
Be a hero in the strife!

He also urges his audience not to get too caught up in thinking about either the past or the future. Instead, they should live in the here and now and undertake meaningful actions.

Act,—act in the living Present!

The advice that the speaker offers is not specifically identified with being a man. “Lives of great men” have provided a source of inspiration for him, and he identifies with his audience in the desire “to make our lives sublime.”

To achieve this “sublime” effect, he recommends achieving things that will be inspiring to those who come after, even though their effects will not last forever. The “[f]ootprints [left] on the sands of time” will remain long enough to help a “forlorn and shipwrecked brother … take heart again.”