We mostly analyze "The Prologue" which is a description of the various persons in the 1300s who Chaucer places in a literary framework of a pilgrimage to St. Thomas Becket's shrine in Canterbury (see "Turbulent" post). He covers all societal classes except the noble class. The feudal system, the working class, and the Catholic Church are all explored through individuals who will tell tales on the journey.
As a precursor to William Shakespeare, Chaucer had a knack for zeroing in on human foibles. He did not try to make judgments but rather allowed the reader to make their own.
The genius lies in the fact that many of the weaknesses in character are relatable to us today. We 'get' certain pilgrims because psychologically, fortunately or unfortunately, humans don't change much over time, thus, we can connect on certain levels.
For example, we must remember that people in "Medieval" times didn't know that term, for them they were living in 'modern' times. Yes, we have seen enormous improvements in the physical conditions of life since the 14th century, however, preachers of that day still condemned society's capacity for cruelty, corruption, and inequality...which could be said today by the 'noble' in our own 'modern' times.
One of the more exemplar tenets of The Canterbury Tales is the considered chasm between thought and practice, especially when it came to Christian orthodoxy. Satirically, Chaucer pointed out this gulf. We would call this difference in word and deed - hypocrisy.
One of the few pilgrims who Chaucer seemed to have unqualified admiration for was a humble, simple Parson, a small parish priest. He lived what he taught and was guided by the notion: "...if gold rust what will iron do/For if a priest be foul in whom we trust/No wonder that a common man should rust..."
As a verb, rust is a destroying agent by outside forces such water, oxygen, and or a corrosive (acid). As a noun it is a brown type of oxide coating on iron/steel caused by corrosive environmental elements. In the Old English, the word rust connotatively meant a "moral canker." It could be applied to an individual whose moral compass was deteriorating based on the blighted powers of pride and greed. If those (authority figures) who were supposed to be the examples to the "rest of us"- crumbled into practices of selfishness, avarice, and blatant hypocrisy then how could others who looked up to them have a 'noble' example to follow?.
"Gold" is expected to be precious and free from the corrupting environmental elements of such temptation. In practical terms, those who say or 'preach' what is important or instruct what others are supposed to do, but then do not back up that belief with deeds and actions cannot be pure like gold. They do not pass the fire test.
The word 'noble', in Chaucer's day was applied to a moral quality in a person, a treasured quality like gold. Yet when the human examples like those in the Church did not practice virtue and integrity, they perhaps were no better than 'rust.'
We are examples. I explain to my students that each one of them is an example. They, however, control what kind of example they are going to be, even if it was or is to another single person. Chaucer's Parson was given noble praise for living a holy life in order to expect his parish to do likewise. He wasn't interested in prestige or wealth. The Parson was a simple example, a good example of what it was to live a humble, yet truth-filled life because he lived what he taught.
We might not be famous, or wealthy, but we should be wise in our thoughts, and our practice should be consistent with what we speak. You can't have it both ways. People are watching you, not just listening to you. Be free from the corrosive coating of rust, which potentially can wear away the virtue of humility and true concern for others.
If you can't be a gold mine in the scheme of things, then be like the Parson, be true and honest in your example and at least strive to be a gold nugget.