Which logical reasoning flaw is demonstrated when a conclusion is supported by a premise that is, in itself, questionable?

The logical reasoning flaw described occurs when a conclusion relies on a premise that lacks validity or is questionable on its own. This is precisely what is known as "Begging the Question," where the argument's conclusion is assumed in its premise without sufficient evidence. Essentially, it creates a circular reasoning scenario where one is trying to prove a point by relying on an assumption that has yet to be established or accepted as true. Therefore, the argument does not successfully establish the truth of its conclusion because it has not provided a solid foundation for its underlying claim. In this way, it undermines logical discourse by failing to present independently corroborative evidence or reasons for the conclusion being drawn.