 We have illustrated the way in which an externalist account of justified belief can exemplify a foundationalist structure by examining one of the most prominent versions of externalism, reliabilism. But other versions of externalism are also implicitly or explicitly committed to a version of foundationalism, or, at the very least, give an account of justification that would enable one to distinguish noninferential from inferential justification, direct from indirect knowledge. Consider, for example, a crude version of the so-called causal theory of knowledge according to which one knows a proposition when one believes it and the belief is caused (in the “right” way) by the very fact that makes true what is believed. On such an account one can distinguish causal chains leading to the belief in question that involve intermediate beliefs from those that do not. Using this distinction, one can again define a distinction between foundational and nonfoundational knowledge: roughly, the causes of belief that do not include other beliefs are the ones that would be foundational  knowledge.[8]