Final answer:
In John F. Carter's work, 'this Thing' symbolizes the problematic world passed down by the older generation to the younger generation, which is fraught with issues and teetering on the brink of catastrophe.
Step-by-step explanation:
The writer, John F. Carter, refers to “this Thing” as the world that the older generation has passed down to the younger generation in a state of disrepair and near collapse. Carter uses the word “Thing” to symbolize the social, economic, and political problems that have accrued over time, leaving a legacy that is “knocked to pieces, leaky, red-hot, threatening to blow up.” This metaphorical description conveys his sense that the older generation has left a world full of problems that can no longer be ignored or accepted with enthusiasm, as it may have been by past generations when it seemed to be in a better condition.