In Chapter 17, Clifford and Hepzibah are riding on a train away from the House of the Seven Gables and Judge Pyncheon's dead body. Clifford uses a metaphor and logos to persuade a fellow passenger that an itinerant life can be more comfortable and all-around better than a life in a house:
But in our ascending spiral, we escape all this. These railroads—could but the whistle be made musical, and the rumble and the jar got rid of—are positively the greatest blessing that the ages have wrought out for us. They give us wings; they annihilate the toil and dust of pilgrimage; they spiritualize travel!
The "ascending spiral" Clifford mentions here is a metaphor he has developed to describe history. He claims that history moves not in a straight line or in a flat circle, but rather in an upward spiral. People today circle back to experiences people had a generation before and a generation before that, but each generation has improved upon these shared experiences. For example, Clifford claims that the railroad has "spiritualized travel." What he means is that passenger trains have taken away the unpleasant bodily experience of travel people used to have. To 21st-century readers, sitting on a train may sound like a cramped experience. To Clifford and other 19th-century travelers, though, watching the world go by through a train window while sitting in relative comfort was a novel experience. Whereas travel once meant bumping along in a dusty wagon, or riding a horse, or even trudging on foot from point A to point B, Clifford is now able to feel his "spirit" fly from one town to the next without his body breaking a sweat. He is unbound from bodily limitations in a way the previous generation never could have imagined. He predicts that future generations will find a way to "spiritualize" travel even further by turning the train whistle into pleasant music and by making the ride even smoother.
Clifford's metaphor allows him to posit that travel is not the uncomfortable experience it once was. The man with whom he is arguing has suggested that it is folly to prefer travel to a life spent relaxing in one's own house. Clifford rebuts by challenging the set of facts the man is working with. A generation before, it may have been more comfortable to relax in a house, but travel has fundamentally changed. Clifford has in fact found it highly uncomfortable to be anchored to the House of the Seven Gables and the sordid history attached to it. Through Clifford, Hawthorne here challenges readers to imagine what it might mean to abandon the notion that owning a house is the key to comfort and happiness. Instead, he argues, there might be a superior comfort and happiness available through the freedom of travel in the industrialized world.