Adapted from my RfA back in December 2010.

Ignore all rules is the triumph of common sense over bureaucracy. One of the oldest policies on Wikipedia, its goal is to keep the focus of the project on its original mission: building a high-quality, comprehensive, free-content encyclopedia. In the end, all policies and guidelines are intended to support that original mission; if a certain interpretation of or loophole in a policy would, if followed to the letter, go against the original mission, it should be ignored, and the right thing done...

Like every other policy and guideline on Wikipedia, however, the interpretation of IAR, and even Wikipedia's original mission, is governed by community consensus. Consensus determines what is an appropriate use of IAR; it is never appropriate to invoke IAR as a justification to do something against policy when consensus does not agree that the use of IAR does in fact further Wikipedia's original mission. For instance, an administrator might believe that Wikipedia's free-content mission would be best served by eliminating all fair use of copyrighted photos. If that administrator then went and unilaterally deleted all images on Wikipedia not licensed under a free-use license, IAR would not be a legitimate defense if the community did not agree that the encyclopedia would be improved by deleting all of the fair-use images. It is understandable that reasonable people would debate the meaning of the original mission and how to balance between the free-content mission and the comprehensive, high-quality mission. Ignore all rules should only be invoked to improve the encyclopedia when the community agrees that the action taken does in fact improve the encyclopedia.

As a personal note, even before I started editing Wikipedia I discovered IAR and found it a remarkable and liberating philosophy. I find that it reminds me to keep my eye on the big picture, and not let rules and legal minutiae get in the way of doing the right thing. No system of rules will ever perfectly cover every situation that could arise in a way consistent with their original intent; in such cases, it is important to follow the spirit of the rules, rather than the letter, because to do otherwise would be to defeat the purpose for which the rules were created in the first place. –Grondemar 22:20, 24 December 2010 (UTC)