I’m truly sorry Man’s dominion
Has broken Nature’s social union,
An’ justifies that ill opinion,
          Which makes thee startle,
At me, thy poor, earth-born companion,
          An’ fellow-mortal!

In these lines (7–12), which comprise the second stanza, the speaker explicitly apologizes to the mouse for accidentally plowing into its nest. The speaker’s words demonstrate that his remorse has more than one layer. Most obviously, he’s apologetic about the physical act of destruction he’s wrought. Yet in this stanza he also links this act of destruction to a larger and even more ruinous tendency that’s bound up with “Man’s dominion” over the earth. This dominion “has broken Nature’s social union” and created antagonism between humans and other animals. Whereas the speaker would like to believe in human–animal kinship, he admits with sadness that the mouse has a justifiable instinct to flee frightfully from humans. It’s also worth noting that, in a poem written in the Scots dialect of English, this stanza stands out for its explicit adoption of formal, philosophical diction.

Thou saw the fields laid bare an’ waste,
An’ weary Winter comin fast,
An’ cozie here, beneath the blast,
          Thou thought to dwell,
Till crash! the cruel coulter past
          Out thro’ thy cell.

These lines (25–30) make up the fifth stanza, which comes halfway through the poem. Here, the speaker attempts to see matters from the mouse’s point of view. He speculates that the mouse built its nest in his field because it had few other options. With the miserable winter weather already on its way and the fields looking barren, the speaker imagines that the mouse attempted to stay warm and cozy by making a temporary shelter underground. But just when the mouse had settled into its new place of residence, a shocking moment of violence destroyed everything. The cruel “coulter” (i.e., cutting blade) of the farmer’s plow crashed right through the mouse’s “cell.” By carefully reconstructing the event that sparked his extended address to the mouse, the speaker reveals how deeply troubled he continues to feel. Furthermore, by reconstructing the event from the mouse’s point of view, he shows a genuine sense of compassion for and kinship with the mouse.

The best laid schemes o’ Mice an’ Men
          Gang aft agley,
An’ lea’e us nought but grief an’ pain,
          For promis’d joy!

These lines (39–42) conclude the seventh stanza, where the speaker offers a pithy summarization of the vulnerability he shares with the mouse. Such a pithy summarization is known as an aphorism. The aphorism the speaker utters here has proven so powerful that it has entered the common lexicon of idiomatic English, in part due to John Steinbeck’s 1937 novella, titled Of Mice and Men. When paraphrased, the lines quoted above mean the following: “Even the most well-thought-out plans often go awry and bring grief rather than happiness.” Significantly, this aphorism doesn’t apply only to humans like the speaker. It applies to any living creature, the mouse included. With this in mind, the aphorism isn’t about “schemes” in a narrow sense. That is, his point isn’t that schemes are necessarily faulty. Instead, he’s saying something about the nature of life. Mice may not make a lot of conscious plans about their future, but even so, they are just as subject as humans are to life’s fundamental unpredictability.

Still, thou art blest, compar’d wi’ me!
The present only toucheth thee:
But Och! I backward cast my e’e,
          On prospects drear!
An’ forward tho’ I canna see,
          I guess an’ fear!

The speaker closes the poem with these lines (43–48), in which he shifts from thinking about what he has in common with the mouse and focuses instead on what’s unique about his position. At the end of the previous stanza, the speaker has just uttered an aphoristic statement about how life is fundamentally unpredictable. That statement explicitly applied both to “Mice an’ Men” (line 39). Here, however, the speaker claims that despite their shared vulnerability, he has it worse than the mouse. The mouse presumably doesn’t think consciously about either the past or the future, and so is concerned only with the present moment. By contrast, the speaker is able to look back on what has gone before, and though he can’t predict the future, he can at least “guess” at what’s coming based on the recent past. This simple fact causes the speaker much fear as he anxiously anticipates his own ruin—a ruin that may or may not actually come. Ultimately, then, what distinguishes him from the mouse is that whereas the mouse has a momentary fear response to a particular event, the speaker suffers from perpetual anxiety about the uncertain future.