According to William Wordsworth in his Preface to Lyrical Ballads, poets draw their subject matter from the passions and emotions of human beings, from the events of human life, and from the natural world. Poetry, he asserts, “is the image of men and nature,” and the poet “considers man in his own nature and in his ordinary life,” looking upon the “complex scene of ideas and sensations” as well as the “great and beautiful objects of nature” that excite the passions of human beings.

For Wordsworth, the key phrase in the broad definition above is “ordinary life.” He believes that poets should work with “incidents and situations from common life” and use the language of common people to describe them. Rustic life, he explains, is closer to nature and to the “essential passions” of the human heart. Its language is “plainer and more emphatic,” and it better expresses human feelings and experiences with simplicity and clarity.

Poetry, Wordsworth, further asserts “is the spontaneous overflow of powerful feelings,” so its subject matter naturally presents the heights and depths of human emotion. The poet has reflected upon these passions, remembering them in the calm of his heart, until they burst forth into poetry that explores and captures the “state of excitement” that arises from feelings and ideas.

Wordsworth chooses his own poetic subject matter according to these qualifications. A glance through Lyrical Ballads reveals poems like “Poor Susan” with its focus on the outcast Susan taking some comfort in the beauty of nature. “The Childless Father” captures a village morning while at the same time reflecting on a father who has lost his child yet must keep living. Wordsworth's famous “Lines Written a Few Miles above Tintern Abbey” delves into the wonders of nature and the ability of the natural world to excite the human mind and heart.