Wikipedia trivia: if you take any article, click on the first link in the article text not in parentheses or italics, and then repeat, you will eventually end up at "Philosophy".

After reading this, I built a little perl script ;)

To check if the above statement is true for a certain article, just enter its name in the text box below.

Idea from this xkcd comic:
Extended Mind

...or get the source of the script from github and start it on your machine (you need to have [[perl|]] installed):