Sidney's long essay Defence of Poesie encapsulates several ideas that are typical of Renaissance thinking.

His primary intention seems to be of showing that the writing of poetry has some special quality that makes it a higher, or especially important, pursuit among intellectual activities. But why? And how is Sidney's view specifically of poetry expressive of the Renaissance mindset? His definition of poetry, following Aristotle, is that it is a form of mimesis or imitation, but it's actually more than that. Poetry does not simply copy Nature, but "grows another Nature," producing something that is in effect better than reality.

In the Renaissance, the breakthrough in thought was that this life, and its pursuits, were to be seen as a kind of end in themselves, not simply a "vale of woe" or a preparation for the next life. If this is true, then man has the ability to advance, and should try to improve himself. Sidney's explicit exalting of poetry as the highest type of endeavor is a corollary of this general attitude. If we can celebrate "this life," without guilt or regrets over doing so, it stands to reason that we can also indulge in an art form that is, if not necessarily an end in itself, an expression of this new-found ability to improve ourselves and to create something better out of nature and of the world than our ancestors could conceive of.

Sidney's own poetry celebrates human love, just as the Italian Renaissance poets Ariosto and Tasso had recently done. In his Defence Sidney talks about the fact that so far, we, the English, have admittedly lagged behind the Romance-language world, not having created poetry on their same level. But this doesn't have to be so, and he uncannily prophesies the ability of the English to achieve greatness in literature. His analysis of the English language also has something about it that relates to general Renaissance thinking. The grammatical simplicity of English, he correctly notes, is a kind of advantage it has over the other European languages. We are not encumbered by complex conjugations as the Romance languages are. His analysis has almost a kind of hedonism about it, basking in our good fortune of having a language unique in its way and with unlimited potential, and this positivity and celebration of simplicity for its own sake typifies the zeitgeist of the 1500s. It's not an coincidence that within a few years of Sidney's untimely and tragic death, Shakespeare, Marlowe, and others would soon fulfill his predictions about the ability of the English to achieve greatness.