There are two types of beliefs: basic and non-basic. Basic beliefs do not require justification because they are non-inferential and self-justifying. Furthermore, this self-justification is achieved because fundamental beliefs are infallible, indubitable, and incorrigible (Steup). On the other hand, non-basic beliefs are inferential and require justification of the basic beliefs to count as knowledge. As a case in point, foundationalism is often demonstrated through the illustration of a tower. For example, core beliefs are the foundation of the tower and support non-core beliefs. Non-fundamental beliefs are also known as superstructural beliefs because they are supported and justified by the fundamental beliefs. To continue, foundationalism can be divided into two forms: privileged foundationalism and experiential foundationalism. The first holds that basic beliefs are limited to internal objects and in particular to beliefs that originate from someone's mental condition (Steup). The second holds that external substances are considered basic beliefs because their justification and evidence derives from experience