Oscar Wilde remarked that Wordsworth wrote about the landscape of the English Lake District but was never really a lake poet: "He found in stones the sermons he had already hidden there." Although there is some truth in this, particularly with regard to Wordsworth's later poetry, it is an unsympathetic reading. Wordsworth's view of nature was in fact remarkably close to Wilde's view of art: something to be appreciated for its own beauty, but also a transformative intellectual, spiritual, and moral force.

This idea of the impact of nature permeates Wordsworth's poetry, but it is more often demonstrated than expressed outright. One of the poems in which Wordsworth is explicit about the effects of nature is "The Tables Turned," in which the speaker urges his friend to stop reading and learn from the beauty of nature instead. The poem contains the famous lines,

Come forth into the light of things,

Let Nature be your teacher.

It would be hard to find a poet more dedicated to nature than Wordsworth. He believed that humankind could be in touch with the divine through nature. He believed, too, that his childhood holidays spent in the English Lake District, where he roamed the countryside freely with his sister, had formed his character by putting him in touch with the simple serenity of God's presence in the natural world.

In his Prelude, his long autobiographical poem, Wordsworth portrayed himself as a second Milton, a poet sage explaining the ways of God to man. Chief among these explanations was his conveying to others his belief that since nature was created by God, God could be experienced through contact with it. Cities, in contrast, being built by men, were corruptions of the divine, taking humans further away from the eternal source of light and love.

In his poems, Wordsworth tried to communicate the healing power of nature and the joy it could bring. For example, in "I Wandered Lonely as a Cloud," he expresses the happiness he felt when, on a walk, he came across thousands of daffodils swaying in a breeze. This experience, so simple and accessible to all people, lifted him with joy as it happened, and he could relive the joy in memory over and over.

A privileging of nature and an appreciation of its beauty and uncorrupted purity are hallmarks of the Romantic mindset. Wordsworth is one of nature's premier advocates, urging all humans to avail themselves of its healing and solace.

Wordsworth sees Nature as, in some sense, a projection of the mind of man. This is typical of Romanticism, with its focus on the inner self, its perception of man as a kind of godlike being, and its concept of the literal outer world as in some way an illusion, a cover of the ultimate reality that lies beneath it. Wordsworth doesn't explicitly or directly express this Kantian philosophical idea that was "in the air" at the time, but it is implied by much of his poetry.

In what might be his most famous work, the "Intimations of Immortality" Ode, Wordsworth links his sense of self (and the immortality of his psyche) to the outside world. As a child, he communed directly with nature and felt something magical and eternal in it; as an adult, he has lost the immediacy of this feeling, but through the remembrance of childhood, he is able to console himself that these "intimations" were real and valid:

Though nothing can bring back the hour
Of splendour in the grass, of glory in the flower,
We will grieve not, rather find strength in what remains behind.

Nature represents a primal innocence that is lost when "the world"—that is, the world of mundane human activity—becomes "too much with us." The poet laments that

The sea that bares her bosom to the moon,
The winds that will be howling at all hours,
And are up-gathered now like sleeping flowers;
For this, for everything, we are out of tune.

These things from which modern man in his maturity (both the maturity of adulthood as well as that of the modern, mechanized age) has become disconnected are not only the things of the natural world, but the older, mythic concepts in which man no longer believes. Wordsworth's wish is that he might

Have sight of Proteus rising from the sea,
Or hear old Triton blow his wreathed horn.

In a former time, man's concepts, just like those of a child in the modern age, were linked to the outer, natural world. Mythology—as in the examples Wordsworth gives at the end of his sonnet—was an outgrowth of Nature, which is itself a part of man's mental cosmos. Much of Wordsworth's poetry is filled with regret, expressing the loss of this innocent union between mind and matter.

Wordsworth was a sincere naturalist and loved unspoiled nature for itself.  However, he also lived out a Romantic philopsphy. As a result, his poetry explores the interaction between the natural world and the human mind.  This interaction took the form of continuous cycle of contacting nature through observation and altering the "thing in itself" (Kant) through meditation.  Wordsworth was aware of the fact that human intelligence often interpreted phenomena in a manner that added to it what may not be visibly present.  One example, might be seen in his propensity to add human values to natural activities.  Such as elevating the work of ants routinely tending to an act of nobility  and wonder.  By creating a worldview based on such insights, one upon layer placed upon the next, Wordsworth came to view the world as wonder the design of which should evoke deep passion in those who correctly observe it.