Welp, the first thing you find out about this poem is that it constantly begins its statements with the phrase "With usura." And in this doing this, Pound hopes to outline all the crummy things in the modern world that he blames on the practice of moneylending with high interest. He specifically uses the Latin form of the word "usury" to give his poem a real "fire and brimstone" vibe to it. Or in other words, he makes usury sound like a super deadly sin just by tacking the Latin "a" ending onto it.
And the biblical tone doesn't stop there. Throughout Canto XLV, Pound keeps up the classical, high-morality tone of voice, saying things like, "with usura/ hath no man a painted paradise on his church wall" (5-6), and the poem pretty much goes on like that until the end. For the most part, Pound spends his time listing all of the wonderful things the world had back in classical times, like great art and great political leaders. He seems a lot less interested in the good aspects of the modern world, like a cure for tuberculosis or houses with running water.
As the poem continues, Pound gets a little more specific about what the modern world is lacking because of usury. He starts listing the names of great artists who, according to Pound, never could have existed in a world dominated by money. "Pier della Francesca," for example, "came not by usura" (29). Or in other words, this Italian painter (who none of us has probably heard of) is someone Pound admires. But the guy could only make his art in a world that cared about beauty more than money, and unfortunately, the modern world has sort of reversed this emphasis, valuing money over beauty.
As the poem winds to a close, Pound throws out the phrase "CONTRA NATURAM" (all caps, in case you missed it). This Latin phrase means, "Against nature," and Pound uses it to say once and for all that usury, greed, and the obsession with money not only go against human nature; they corrupt and ruin nature in general. They're just the worst. According to Pound, modern greed has completely warped our relationship to the natural world, and if we don't get our priorities straight, we'll all die and turn into a bunch of "Corpses […] set to banquet" (49). Lovely. Whether Pound means this literally is unclear, though it probably doesn't matter. If we die in our spirits, we're as good as dead in our bodies, too.