"A Psalm of Life" might certainly be described as morally uplifting, sentimental or both. Longfellow certainly intended the poem to provide moral uplift, at the least, and claimed to have met at least one man who told him that reading it had persuaded him not to commit suicide. It is clear from the text that the poem is intended to be morally uplifting since the poet is so constantly hortatory and didactic. The tone is supremely confident, as Longfellow briskly dismisses the psalmist's mournful view of life, asserts what life really is, then spends the rest of the poem telling the reader how best to live. He preaches altruism, saying that we should leave "footprints on the sands of time" to inspire and hearten others as we have been inspired and heartened by the great men of history.

It is precisely this type of moral uplift, however, that is likely to strike the modern reader as sentimental. We do not know precisely which "great men" Longfellow had in mind, but given that he is primarily concerned with their legacy, he is probably referring to the leaders and explorers after whom countries or cities are named: Christopher Columbus or George Washington. These figures are no longer the objects of the uncomplicated admiration they attracted in the nineteenth century, and the very idea of modeling oneself on the great figures of history now seems rather sentimental, as does the optimistic insistence that hard work and persistence (rather than, for example, wealth and influence) are a certain route to success.