Frost's poems deal with man in relation with the universe. Man's environment as seen by frost is quite indifferent to man, neither hostile nor benevolent. Man is alone and frail as compared to the vastness of the universe. Such a view of "man on earth confronting the total universe" is inevitably linked with certain themes in frost's poetry.
One of the most striking themes in Frost's poetry is man's isolation from his universe or alienation from his environment. Frost writes in "Desert Places", "The loneliness includes me unawares". Man is essentially alone, as is borne out in frost's poetry. Frost is not so much concerned with depicting the cultural ethos of New England people as with presenting them "caught up in a struggle with the elementary problem of existence". The New England of Frost reflects his consciousness of "an agrarian society isolated within an urbanized world". Man is alone in the countryside or in the city in "Acquainted with the Night".
I have stood still and stopped the sound of feet
When far away an interrupted cry
But not to call me back or say good-by;
In "Home Burial", the lady suffers from a terrible sense of self-alienation, as well as alienation from her surroundings. And, more than the physical loneliness, man suffers from the loneliness within.
I have it in me so much nearer home
To scare myself with my own desert places.
A concern with barrier is the predominant theme in Frost's poetry. Man is always erecting and trying to bring down barriers-- between man and environment, between man and man. To Frost, these barriers seem favorable to mutual understanding and respect. Frost insists on recognizing these barriers instead of trying to tear them down as in the modern trend. And he even builds them wherever necessary.
Practically all of Frost's poems depict the theme of human limitation. The universe seems chaotic and horrific because man's limited faculties cannot comprehend its meaning. Walls, physical and real, mental and invisible, separate man from Nature. "Neither Out Far Nor In Deep" shows man's limitation concerning the mysterious universe. "Stopping by Woods on a Snowy Evening" conveys the sense of an impenetrable and indefinite universe. Frost's human beings are aware of the gap between the ideal and the actual. The apple-picker had set out on his work with great hopes, but faces disillusionment.
For I have too much
Of apple-picking: I am overtired
Of the great harvest I myself desired.
In some poems, however, Frost does indicate that man can exceed his limitations in his thought as in "Sand Dunes".
Theme of extinction or death also runs through the major themes of Frost. In many a poem he writes of "sleep" which is associated with death. "Fire and Ice" is a noteworthy poem on destruction by excess of desire or hatred. "Stopping by Woods on a Snowy Evening", "After Apple Picking", "An Old Man's Winter Night", all these poems have a reference to death. "Directive" is a poem in which three of Frost's most obsessive themes isolation, extinction and the final limitations of man are blended. Each life is shown to be pathetic because it wears away into death. The poem dismays but it also consoles.
In most of Frost's poems, the speaker undergoes a process of self-discovery. The wood-chopper of "Two Tramps in Mud Time" realizes by the end of the poem that he chops wood for love of work only but love and need should not be separated.
Theme of affirmation is also found in some of his poems. Frost ultimately presents the need for man to make the most of his situation. Aware of man's limitations, he yet desires man to explore and seek knowledge and truth. Man should learn to accept things and his limitations cheerfully. He suggests stoical will and effort in the face of adversity as in "West Running Brook". In the face of the mystery and riddle of life there is necessity for determined human performance.
But I have promises to keep
And miles to go before I Sleep
And miles to go before I Sleep
Theme of love is central to Frost's poems. If there is any force that can help man meet the challenges of the universe, it is love. In several of Frost's poems, the significance of love between man and woman, or friendly love is brought out. It is when love breaks down or fades off that life becomes unbearable especially for the women in Frost's poetry.
The major themes as discussed above are expressed through various devices. The symbolic significance invested in certain recurring objects like the stars, the snow, the woods serve to bring home to the reader all the more vividly the position of Man in the Universe.