CIRCULAR LOGIC:
not always a bad thing:
elelctricity requires a functional circle as a circuit to properly function in devices as DC.. if you break the circle/circuit anywhere than your system is off.
the problem is when don't like the cycle / loop that is repeating as a pattern.. or when nothing in the circlular logic can be verified thus you can't assume the rest of the circle is true based on anything in the circle... but if the logic is sound; if anything in the circle can be verified it should all be true.. be it a desirable circle or not.
circles are useful for many things.. but when someone abuses the logic to trick someone and pretend like the circle is what makes it good or bad.. people get confused.