   Ultimately, we think that such arguments lead to their conclusions because we accept certain logical principles—such as the law of non-contradiction, or modus ponens—which appear to us to be self-evident. But to say that such principles are self-evident is just to say that we cannot help but accept them. It is not to offer any non-circular justification of those principles. But the irresistibility of a belief is a very good indicator, Reid thinks, that we hold that belief merely because of the way we are built, merely because of our constitution. But then the skeptic has merely placed the skeptical conclusion on the same footing as the common sense belief about the external world: both rest on something that we are compelled to believe by our constitutions. However, in order to overthrow common sense, the skeptic must place the skeptical conclusion, rather, on a firmer footing than the common sense conclusion. Thus, the skeptic gives us no reason to reject common sense beliefs about the external world. Reid has defended common sense through construction of a direct theory of perception that avoids the pitfalls of the Way of Ideas' representational theory. Rather than landing in the “coal pit” of skepticism, as Reid calls it, his theory purports to deliver knowledge of the external world.