Most likely written in 1579, but not published until 1595, Philip Sidney's Defence of Poesy is a new response to an old charge against the legitimacy of poetry, one that had been leveled against the literary arts at least since Plato in The Republic. Plato was ready to jettison most poetry from his ideal state because, he argued, poets were irresponsible and could deceive and mislead citizens. These same concerns were taken up with vigor by many activist religious groups who gained power during Philip Sidney's time, in particular the Puritans. One particular spokesperson for the Puritan claim to the moral high ground was especially central to Sidney’s decision to craft his defense: Stephen Gosson, whose anti-poetic pamphlets included School of Abuse and Plays Confuted in Five Actions. As often happens in these cases, Gosson was himself a playwright, but excused his own writing from the attacks he made against poetry on the grounds that they were of a higher moral order than most other literary arts.
Sidney's defense of poetry takes the form of a classical, seven-part argument to establish that poetry has been respected in all cultures up to Sidney's time and that it is more effective than history or philosophy in its ability to lead man towards virtuous action. In support of these points, he directly counters Gosson's claims that poetry is the "mother of lies" and an inspiration to lust and sin. Sidney seeks to divide Poetry proper from the flaws of individual poets, and of individual genres or "parts" of Poetry writ large (thus also countering the historical argument that Plato disapproved of all poetry). Having made his defense, Sidney suggests that England should form a strong national tradition of poetry, and concludes by asking his countrymen to believe in poets and even write poetry. He casts a curse on all those who still hate poetry.
Sidney was just one writer of the time to take exception to Puritan hypocrisy, but it is his Defence of Poesy which has stood the test of time. Indeed, many scholars regard his eloquent defense against Plato and Gosson's attacks on poetry to be the first real example of literary criticism. It inspires later defense of poetry, perhaps most notably Percy Bysshe Shelley's similarly titled "A Defence of Poetry."