Divided, they come together

English-speaking America’s first great mystic was a naturalist, and Henry David Thoreau’s spirit hovers like an animating angel over “The Expeditions,” Karl Iagnemma’s emotionally powerful and beautifully wrought first novel.

Iagnemma is a prize-winning short-story writer, and his first collection, “On the Nature of Human Romantic Interaction,” created a justifiable stir when it was published several years ago. Writing, however, is the author’s second career. By day, he works as a research scientist in MIT’s department of mechanical engineering helping to design robotic vehicles like those now exploring Mars.

There must be something in the water at MIT, where the novelist Alan Lightman -- the author, most recently, of the novel “Ghost” -- also teaches physics. Like his colleague, Iagnemma is simultaneously concerned with the large questions growing out of the interrelationship of faith and reason and with the more intimate issues of love, forgiveness and reconciliation. Simply blending those themes into a single intelligible narrative would make for a fairly ambitious first novel. Iagnemma kicks up the degree of difficulty by setting his story in mid-19th century Michigan, a time and place he evokes in stunningly credible detail.

The year is 1844, and 16-year-old Elisha Stone, a runaway from rural Massachusetts, has made his way to Detroit, then a turbulent, polyglot frontier town and a jumping-off point to the newly acquired and largely unexplored lands in Michigan’s Upper Peninsula. Elisha, whose father is a Congregationalist minister, has been well educated by his parents and tutored in drawing by his doting mother. Like Thoreau, he has spent long solitary hours simply observing nature, finding there a transcendent but concrete beauty. Elisha’s most recent work has involved cataloging and labeling a collector’s vast accumulation of mounted birds and animals, shells, minerals and other natural artifacts. The young man dreams of a collection that would encompass all of nature in coherent arrangement.

He’s hungry for scientific experience and, down on his luck, he’s just plain hungry. In Detroit fortuitous circumstance presents itself in the form of a small expedition forming to explore the Upper Peninsula, which has been acquired from Great Britain. The party is to consist of two scientists -- an ambitious ex-soldier turned surveyor, Silas Brush, and a crackpot proto-anthropologist, George Tiffin, eager to prove his novel theories on the Indians’ “real origins.” Elisha is taken on as packer and assistant to both men. Their party was to have been guided by a French Canadian trapper, who fails to turn up. His place is taken by his wife, a mysterious woman of both English and Chippewa parentage. (Shades of Charbonneau, Sacajawea and the ur-American expedition undertaken by Lewis and Clark. This novel abounds in such subtle historical and writerly evocations; the expedition’s course, for example, takes its members past the Two Hearted River, scene of the greatest of Ernest Hemingway’s Nick Adams stories.)

The title of Iagnemma’s novel is plural, however, and Elisha’s journey is spur to another, even more improbable odyssey. The young man left home in estrangement and disgrace, pocketing the Sunday collection on his way out the door. He has not communicated with his parents for three years. On the eve of his departure for upper Michigan, he sits down and writes a letter to his mother. It concludes:

“I would explain my disappearance from Newell and my absence these past years, but any words I might write seem pale shadows of my true thoughts. Know that not a day has passed that I have not dreamed of home. Mother, this country is more mean and solitary than I had ever imagined. In my dreams Newell seems part of a different world entirely. . . . Dear Mother, I have missed you with every part of my heart. My mood is lifted only by the hope that I might see you again, very soon.”

What Elisha cannot know is that his consumptive mother died weeks after he fled their home. When his letter arrives, it is opened by his father, the Rev. William Edward Stone, who is himself ill with consumption, addicted to a patent medicine and increasingly beset with doubts about his vocation. Reading his son’s letter, the older man gradually comes to the realization that they had estranged themselves from each other through their different reaction to the mother’s final illness. It’s a realization at once shattering and energizing and the Rev. Stone, who hardly has left his rural Massachusetts village since taking the pulpit there, decides he must go in search of his son and tell him of his mother’s death.

This is the second, parallel “expedition” in Iagnemma’s narrative, which cuts back and forth from the son’s journey to the father’s. Neither proceeds as the protagonists envisioned. Elisha’s is, at once, more freighted with beauty and disillusionment than he ever could have imagined. The Rev. Stone’s expedition is more arduous and, in some ways, more degrading than he ever could have imagined and yet more liberating.

In fact, one of this novel’s many and considerable strengths is the way in which the author refuses to stack the decks for or against either of his protagonists or their prospective ideas -- the man of faith and the man of science. Each has his flaws and each his admirable strengths.

What they share is an elemental delight in the beauty of nature and daily life and an unshakable integrity that ultimately makes possible their appreciation of nature’s intimations of the transcendent. One thing that enhances the story’s emotional credibility is that, different and distant from each other though they may be, as you watch Elisha and William proceed on their parallel “expeditions,” you gain a clearer and clearer sense of the younger man as his father’s son.

That, of course, brings us back to that “inspector of snow storms.” On Jan. 21, 1852, Thoreau wrote in his journal, “A man does best when he is most himself.”

timothy.rutten@latimes.com