Some beliefs are built upon other beliefs.
| Descartes was born in 1596. | |||
| Pojman wrote that Descartes was born in 1596. | Pojman would not be wrong about the birth year of Descartes. | ||
| The publisher is careful about what it allows to be published in its books. | Pojman has studied philosophy and knows it well. | ||
If one of the foundational beliefs is mistaken, then the support for our belief built upon it is undermined.