Circular Reasoning

Circular reasoning is a logical fallacy in which a person assumes the truth of what they are trying to prove, effectively using the conclusion as a premise in their own argument. This type of reasoning is also referred to as "begging the question" (petitio principii) or "assuming the initial point." It is a fallacy because it does not provide any independent evidence or information to support the argument — the reasoning simply goes in a circle.

Circular reasoning usually involves a person making a claim and then restating that same claim in different words as though it were supporting evidence. For example, someone might say, "This is the best restaurant in town because no other restaurant is as good." This statement is circular because the "reason" offered (no other restaurant is as good) is merely a restatement of the conclusion (it's the best restaurant), not independent evidence.

Circular reasoning can also occur when a person relies on an unstated assumption that itself depends on the conclusion. For example, someone might argue, "God exists because the Bible says so, and the Bible is true because it is the word of God." This is circular because the authority of the Bible is grounded in God's existence, which is the very thing being argued for.

Circular reasoning can also occur when a person uses a definition to define itself. For example, someone might say, "A sleeping pill works because it has a dormitive property." This statement is circular because "dormitive property" simply means "the ability to cause sleep" — the explanation merely restates the observation in fancier words without actually explaining anything.

In summary, circular reasoning is a logical fallacy in which a person's argument ultimately relies on the very conclusion it is trying to establish. It is a fallacy because it provides no independent support for the claim. Common forms include restating the conclusion in different words, relying on assumptions that presuppose the conclusion, and offering definitions that merely restate what they claim to explain.