Geoffrey Chaucer is known primarily not only as a poet, but also as a man with an extraordinary gift of looking at his subjects and the context of the time in which they live to provide an unparalleled vision into the daily existence of medieval persons from all walks of life and social strata. His "shrewd observations" brought alive some of literature's most memorable characters.
Though Chaucer came from humble beginnings himself, the variety of professions in which he was employed exposed him to all kinds of people. It was, however, his keen sense of observation through which he was able to make the best use of his myriad of experiences.
Another compelling aspect of Chaucer's work is that rather than writing in the language popular to the time (Latin—the Roman Church's language) or French (the language of royalty and nobility—after the conclusion of Norman invasion of England by William the Conqueror around 1066), Chaucer wrote in the language of Middle English allowing that the common people (the emerging middle class) would have access to his work.
And if that is not enough, Chaucer was completely honest about what he witnessed in the behaviors of a wide variety of people from many classes.
For instance, in The General Prologue to the Canterbury Tales, the Knight is held up as a man of humility and nobility of character. He fought for what he believed in as if it were his life's breath, but rather than receiving accolades for his work, he returned home to immediately take a pilgrimage in order to give thanks to God. Chaucer greatly admires the Knight:
There with us was a KNIGHT, a worthy man
Who, from the very first time he began
To ride about, loved honor, chivalry,
The spirit of giving, truth and courtesy.
On the other hand, Chaucer was also brutally honest about the servants of the Church. All but one of his characters that serve the Church demonstrates the worst possible behavior. The Pardoner, for example, sells "hot" (stolen) pardons, to the poorest of people—most living in poverty—which believe their sins will be forgiven for purchasing the pardons. Also:
...in his bag he had a pillowcase
That used to be, he said, Our Lady's veil;
He claimed he had a fragment of the sail
That took Saint Peter out upon the sea
Before Christ called him to his ministry…
The Friar is more interested in the ladies, and in hunting and singing. As servants of the Church were expected to put away worldly goods and practices and serve as shepherds to God's flock, neither the Friar, the Pardoner nor the Nun (the Prioress) does so. Only the Parson was a worthy man of the Church. Chaucer allows the reader to see that though he has little, he gives what he has to the poor, following the true meaning of the "servant" to his flock.
However, in the manner of a true and gifted poet, Chaucer never tells the members of his audience what they should think. He presents the facts and allows the reader to draw his/her own conclusions regarding the characters he presents.
In terms of Chaucer's work from a structural standpoint, Chaucer specifically uses the pilgrimage as a framework: for this was perhaps the only event of that era when people of all backgrounds and classes would come together, enabling the author to present to the reader with a brilliant cross-section of society at that time.
Chaucer also changed the structure of the poem, something that would impact writers for generations to come:
Chaucer’s [poetic] practice established accentual syllabic meter as the norm of English verse for five centuries thereafter. Beginning with the four-stress lines of The Book of the Duchess and The House of Fame...Chaucer developed the five-stress line which became the backbone of the major poetry of William Shakespeare, John Milton, Alexander Pope, William Wordsworth, and many others.
Chaucer changed the face of literature, impacting what it has become for the modern-day poet. He was not afraid to be honest to his craft. He did not follow the prescribed methods of the day: he wrote in a language accessible to the masses. He inferred; he did not tell his reader what to think. (Chaucer pretends to be one of the members of the pilgrimage, thereby making himself a more credible source for his readers to offer his observations—another way in which he shows that he is a maverick of his day.) Additionally, Chaucer's diction (word choice) more easily allows the reader to weigh the character of each member of the pilgrimage. In this way, there was room for discussion and interpretation. He also introduces the use of a meter (rhythmic pattern) unfamiliar to audiences up to that point.
Chaucer is a modern poet in that he is not afraid to try something different. Also he is able to provide barely perceptible nuances that delve into the deepest and truest dispositions of his subjects. He uses excellent sensory details to create a world for the reader that is unfamiliar—moreover, he is able to bring to life (without personal judgment) characters that fairly fly off of the page.
In defining modern poetry, Kenneth Goldsmith, in his article entitled, "The Challenges of Twenty-first Century Writing," he notes:
Success lies in knowing what to include and — more important — what to leave out […] While all words may be created equal — and treated thusly — the way in which they’re assembled isn’t; it’s impossible to suspend judgment and folly to dismiss quality.
By referring to these more modern perceptions—even expectations—of a poet's responsibilities to his/her art, Chaucer (who started a new movement in poetry that influenced so many great authors that would follow him) seems to live up to these expectations. Perhaps it is because of the example that he set, that modern poets have such high expectancies. I believe that Chaucer would commend them for their efforts.