Bloom argued that poets are hindered in their creative process by the ambiguous relationship they necessarily maintained with precursor poets. Because all poets are inspired to write by reading another poet's poetry, they tend to produce work that is derivative of existing poetry, and, therefore, weak. Because a poet must forge an original poetic vision in order to guarantee his survival into posterity (i.e., to guarantee that future readers will not allow him to be forgotten), the influence of precursor poets inspires a sense of anxiety in living poets. In this first book, Bloom attempted to work out the process by which the small minority of 'strong' poets manage to create original work in spite of the pressure of influence.
Prior to writing this book, Bloom spent a decade studying the Romantic poets of the early nineteenth century. This is reflected in the emphasis given to those poets and their struggle with the influence of John Milton.
In The Anxiety of Influence and other early books, Bloom claimed that influence was particularly important for post-enlightenment poets. He suggested that influence was not as much of a problem for such poets as Shakespeare and Ben Jonson. He since has changed his mind, and the most recent editions of The Anxiety of Influence include a preface demonstrating that Shakespeare was troubled throughout his career by the influence of Christopher Marlowe.