vicious circle (thing)

1. A situation in which the response or solution to a problem gives rise to another problem, and the response to this new problem leads back to the first problem, often with additional complications.

• A country attempts to increase income in a product by boosting exports; this floods the market, further lowering prices; in turn, even greater production and sales are required to maintain income, and so on.

2. A logical fallacy in which the conclusion of an argument is used to support the premises upon which the argument is based.

• God exists, because the Bible tells me so. I know the Bible is true, because it's the Word of God.

Vicious circularity is also a property of paradoxes:

• Epimenides, the Cretan, says, "All Cretans are liars." - Eubulides