Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page Problem of the criterion:

This text is part of the article's lead section, so referencing it may be optional. Please see WP:CITELEAD for more information.

"

An answer to either set of questions will allow us to devise a means of answering the other. Answering the former question set first is called particularism, whereas answering the latter set first is called methodism. A third solution is skepticism, which proclaims that since one cannot have an answer to the first set of questions without first answering the second set, and one cannot hope to answer the second set of questions without first knowing the answers to the first set, we are, therefore, unable to answer either. This has the result of us being unable to justify any of our beliefs.[citation needed]