Snippets from the mailing list charter[0] and listinfo[1] which simply say briefly:

    About Full-Disclosure

    Unlike bugtraq, this list serves no one except the list members themselves
    We don't believe in security by obscurity, and as far as we know, full 
    disclosure is the only way to ensure that everyone, not just the insiders 
    have access to the information we need to survive.

    We will try to operate this list without moderation, as we feel moderation 
    is an impediment to communication. 

    Any information pertaining to vulnerabilities is acceptable, for instance 
    announcement and discussion thereof, exploit techniques and code, related 
    tools and papers, and other useful information.

and, forebodingly:

    Politics should be avoided at all costs.

There's also the original announcement on the SuSE Linux security mailing list[2] and a follow-up by Mr Cartwright with some further rationale[3].

[0] https://web.archive.org/web/20050306210635/http://lists.nets...

[1] https://web.archive.org/web/20041205194605/http://lists.nets...

[2] http://marc.info/?l=suse-security&m=102639105014466&w=2

[3] http://marc.info/?l=full-disclosure&m=102965261426089&w=2