The use of money causes a civilization to decline. That this is true

If you aren't sure about the conclusion, ask yourself, "Why is this passage here? What is the author trying to do?" Is the author's main point that "the troubles of Western civilization began with the invention of money" or that imitation money is worse than real money? As a test, try putting the word "therefore" in front of the part you believe to be the conclusion. Does the rest of the passage form an argument supporting that conclusion?

Does the author tell us that "the use of money causes a civilization to decline" as evidence to support that "the decline of Western civilization exactly parallels the increasing use of money as a substitute for things of intrinsic value"? No, in fact, it is the opposite. Everything in the passage after the first sentence forms an argument that logically leads to the conclusion that, "[therefore], the use of money causes a civilization to decline." The phrase, "that this is true is shown by..." is a hint that the previous sentence was your conclusion. The author starts with a statement and then explicitly says that what follows will support that first statement.

Once you've arrived at the conclusion or purpose of a passage, make sure you understand how the author arrives at that conclusion or purpose:

• "the troubles of Western civilization began with the invention of money" - If this is true, it would be evidence supporting (not proving) the author's conclusion.
• "The decline of Western civilization exactly parallels the increasing use of money—both real money and worthless paper money—as a substitute for things of intrinsic value." - Okay, if the decline of Western civilization exactly parallels the increasing use of money, then, again, this would be evidence supporting the author's conclusion. But why is money bad for a civilization? We aren't told why specifically, but we can infer that using money as a substitute for things of intrinsic value is bad for a civilization.
• "While real money (gold and silver) is bad enough, imitation money (paper money) is a horror." - This statement supports the inference that using money as a substitute for things of intrinsic value is bad for civilization. In other words, "real" money (gold and silver) is bad enough because it is a substitute for things of intrinsic value. "Imitation" money is even worse because it is a substitute for "real" money (a substitute for a substitute!).

I hope that helps!