Thomas Carlyle is often considered one of the great prose stylists of the Victorian period, and the passage quoted above has often been cited as an especially accomplished piece of writing, particularly in its use of sentence structure, comparison, and imagery. Analysis of the passage in those respects might include the following points:

• Sentence 1 is balanced in its structure, pivoting on the semicolon and both opening and closing with references to blessedness.
• In sentence one, the comparison and imagery involve religion: a person who has found his right vocation is “[b]lessed.” The entire passage even sounds like a sermon.
• Sentence 2 picks up the key word from sentence 1 (“work”) and develops it more fully. Once again, sentence two is balanced, with the two halves marked by the semicolon. In turn, the second half of the sentence is also balanced, pivoting on the comma.
• Sentences 1 and 2 are relatively brief and relatively free of imagery. In contrast, sentence 3 is very long and develops at great length the comparison of work to free-flowing water. The imagery of the “sour mud-swamp” implies stagnation and filth. Work is associated throughout this lengthy sentence with life and energy and beauty; existence aside or apart from work is associated with sickness and inertia and ugliness. The sentence both begins and ends with imagery comparing work to a flowing stream.
• Sentence 4 returns to the theme of blessedness and unites that theme with the imagery of streams and meadows from sentence 3. Sentence 4 is also an exclamation, a fact that again makes this passage sound like something from a sermon.
• Sentence 5 opens with a very abrupt comparison that is emphasized not only by its brevity but by the use of alliteration. Notice the use of capital letters for emphasis on this sentence. Notice how Carlyle stops to define “Force,” and the lofty, sublime language he uses to do so. Earlier the passage had emphasized blessedness; now God is brought explicitly into the phrasing. Work is now compared to the breath of life given to us by God. Sentence 5 rolls on and on, phrase added to phrase as Carlyle reaches a kind of rhetorical climax. The language here is more abstract than in the earlier very long sentence (sentence 3). That sentence had emphasized imagery; this sentence emphasizes concepts.
• Coming after such a long sentence, the one-word sentence fragment of sentence 6 is all the more startling and emphatic. All the more intriguing is that the fragment is a question. Carlyle momentarily encourages the reader to think before answering the question himself in sentence 7.
• In sentence 7, as earlier, Carlyle picks up a key word from a preceding sentence and then elaborates upon it at length. Sentence 7 also once again seems rhetorically balanced, especially in the groups of four words that precede both the semicolon and the period.
• Sentence 8 compares hypotheses to subjects for school debates, to things floating in clouds, and to small whirlpools. The latter two of these three comparisons use natural imagery, as Carlyle had earlier done in sentence 3.
• Finally, sentence 9 ends the passage emphatically. Its subject is doubt, but its tone is not doubtful at all:

“'Doubt, of whatever kind, can be ended by Action alone.'”

Carlyle's famous passage makes effective and memorable use of sentence structure, comparison, and imagery, among various other techniques.