The vigorous, meandering notebooks of Robert Frost

More than 40 years after his death, Robert Frost remains America's quintessential poet and perhaps its least understood. So much of his work appears simple on the surface, while dark, mysterious currents swirl beneath. If there were a key to unlock those hidden riches, or explain the dualism throughout, many would eagerly buy it.

What some may reach for instead is The Notebooks of Robert Frost, a collection of his private jottings now being published in their entireity for the first time. Here, readers will find access to the thoughts and observations of the four-time Pulitzer Prize winner.

These do not include, however, glimpses into Frost's personal life, his private pains, or family stories. Nor do these notebooks offer explanations of his work.

What can be found is intellect in action, as Frost explores literature, history, philosophy, and religion. The voice is similar to that in his verse – clear, authoritative, sometimes sharp or funny – but the currents flowing through these pages predate those in the poetry, meaning that the water is colder and deeper, not a warm, easy dip.

Editor Robert Faggen, the preeminent Frost scholar, does help readers take the plunge. His introduction to the notebooks, more than 40 in all, is insightful and pitch-perfect.

"His poetry has become to many an alternative to the complexity and despair of modernity," Faggen writes, "Yet Frost himself emphasized the ephemeral quality of moral order and often took pleasure in uncertainty and chaos."

That complexity colors the notebooks, whether Frost is jotting down aphorisms, lines for a poem, or lecture notes about writing and art. The thinking is rigorous and bold, and often explores "dark sayings," proverbs or ideas that require deep thought.

Take, for example, these sentences: "The mind of man is an unvicious circle that no desperation can break through. Knowledge is the same."

Faggen begins each section with a physical description of the notebook, many of which were dimestore spiral pads. He also annotates some of Frost's more cryptic references and highlights thematic connections. He does not play tour guide, however; readers must explore the wilderness themselves.

Those who are willing to do so will discover many gems, such as this advice to students in Notebook 4: "Don't tell the poem in other and worse English of your own to show you understand it. But say something of your own based on the poem (not an opinion of it though)."

Frost's ideas aren't always that cogent, however, since a notebook is the mind's playground. Many entries read more like this, in Notebook 4:

"Nothing more social than to work alone
"Life catches on something to resist itself

"To put love in its place so it will hold a while. The fallacious think poetry must be on the side of love's not being put in its social place. Poetry is on both sides."

Frost's commitment to disciplined thinking is evident throughout, especially when he explores the relationship between it and poetry or any pursuit. Not everyone agreed with his standards or ideas, including many of his students, who felt they didn't need instruction.

"We reached an agreement," he wrote, "that most of what they regarded as thinking, their own and other peoples, was nothing but vote-taking sides on an issue they had nothing to do with laying down."

The Frost in this tome is complex and challenging. Instead of one clear portrait, he emerges from a collage made from thousands of moments. This may satisfy scholars, who are likely to find Frost's notebooks an invaluable asset.

Lay readers, on the other hand, may wish that Faggen had provided detailed commentary throughout. His words open the notebooks in significant ways, and for many of Frost's readers, more of that illumination is needed.

• Elizabeth Lund writes on poetry for the Monitor.