Milton's poem has produced mixed reactions in the three centuries since its first publication. Much of the controversy surrounding the poem centers around two main issues: its style, and its content (specifically its religious subject matter and political overtones). Yet, it must be remembered, in the epic form style and content are closely related, and it is thus impossible to separate the two issues entirely.

Early reactions to the poem seem to have questioned Milton's use of blank verse in an epic poem, and the second and third issues of the first edition contain a note from "The Printer to the Reader'' on this subject, as well as Milton's own justification of "The Verse." However, the most intense reaction to the poem in its early days focused on its content. Nicholas von Maltzahn ("The First Reception of Paradise Lost (1667)") summarizes the politics surrounding three early responses which typify its first reception. The episcopal licenser, Thomas Tomkins, was at first inclined to suppress the poem, finding evidence in it of the anti-royalist sentiments for which Milton was notorious after the publication of his tracts supporting the regicide of Charles I. After the Restoration, such opinions were, naturally, cause for profound concern. Tomkins disapproved of the emphasis on astrological omens, such as eclipses, which reflected a Puritan tendency to over-emphasize natural events, and which Tomkins feared would fuel dissent in the wake of numerous disasters which the English had suffered in the previous year (such as the Great Fire of London). Tomkins was also suspicious of Milton's elevation of private illumination or inspiration. However, other preoccupations also engaged Tomkins, and in a time of national crisis, Milton's emphasis on reason, first principles and common notions, and the poem's engaging development of sacred history were seen as contributing to, rather than detracting from the stability and national unity which Tomkins sought to endorse. He therefore licensed the work, in spite of his misgivings.

The initial success of the poem is seen in the reactions of Sir John Hobart, who saw the Christian epic as a welcome balance to the decadent culture of the court. While joining in the (by now) almost universal condemnation of the politics represented in Milton's prose, Hobart praised Milton's humanism, as well as his style, which he stated was "not only above alle moderne attempts in verse, but equall to any of the Antient Poets'' (letter, Bodl. Ms Tanner 45, cited by von Maltzahn). John Beale, however, had a more mixed reaction. Beale responded hopefully to Milton's claims to individual inspiration, and his elevation of the claims of conscience. Yet, he was wary of the politics of Paradise Lost, which he saw as openly republican, as well as its demonology, which was too Calvinist for his episcopal tastes.

Criticism of Milton's epic has continued to be divided. Early poets and critics who have praised Milton's style and content include John Dryden, who in 1688 placed Milton on a level with Homer and Virgil Patrick Hume, who published an early annotated text of the poem in 1695, and Joseph Addison, who published a laudatory series of essays in 1712. Samuel Johnson, however, was less complimentary, writing, "Paradise Lost is one of the books which the reader admires and lays down, and forgets to take up again. None ever wished it longer than it is. Its perusal is a duty rather than a pleasure."

The greatness of Milton's verse was generally acknowledged in the nineteenth century, and his influence on poets such as William Wordsworth, Samuel Taylor Coleridge, Percy Bysshe Shelley, John Keats, Alfred, Lord Tennyson, and Matthew...