Perhaps a Hanlon's Razor, but what does it mean?
Solution 1:
The sentence you provide, Hasin, is not the same as "Never attribute to malice that which can be adequately explained by stupidity," which as Gnawme points out, is an adage known as Hanlon's Razor.
Hanlon's Razor includes the moral premise that you should "assume good faith" is at work, even though damage has occurred, whenever possible. Alexandre Dumas is reputed to have once said, "I prefer rogues to imbeciles, because rogues sometimes rest." He was implying that idiots actually do more damage than miscreants, because they are incapable of doing anything constructive. Therefore, he seems to be implying, when witnessing destruction, one should first assume that incompetence is to blame, and then investigate malice.
This boils down neatly to the BritE expression "Cock-up before conspiracy", describing where to start in trying to determine the reason for some mishap. The expression is attributed to Bernard Ingham, press secretary to Prime Minister Margaret Thatcher from 1979 until her resignation in 1990.
The rule that you quoted actually reads, "Any sufficiently advanced incompetence is indistinguishable from malice", and is known as Grey's Law, though it seems recent in origin and there seems to be no record of a person named Grey saying it, nor any verifiable reference linking it to a person named Grey.
You will note that there is no moral guidance in this Law. What it actually suggests is that when severe incompetence is at work, it will probably spark accusations of malice, in part because few are willing to accept that such extensive damage could result from mere stupidity. It also warns that the two causes are superficially indistinguishable, and that such accusations may be unwarranted, no matter what the scale of damage.
Presumably, before the incompetence is sufficiently advanced, it is easily distinguishable from malice. What about after incompetence reaches the point of being indistinguishable from malice? Does the rule imply that when incompetence is further advanced, malice becomes the prime suspect? That's my interpretation, but while it's the result of logical induction, it's arguably subjective.
Solution 2:
It's the original Hanlon's Razor
Never attribute to malice that which can be adequately explained by stupidity.
cast in the form of Clarke's Third Law:
Any sufficiently advanced technology is indistinguishable from magic.
Loosely translated, it means that someone might have done something because they were just stupid, and not because they wanted to do you harm.
For example, someone who almost ran you down in a crosswalk with their car was probably just careless and inattentive, and not actually trying to kill you.
Solution 3:
Since there seems to be some fluidity to the Wikipedia information (viz, edited yesterday apparently to remove the reference to J. Porter Clark as the source of the aphorism, since it no longer appears there, but was present when I wrote my answer), here is Mr Clark's original Usenet post, in its entirety. This should resolve the matter. He does, in fact, use the term "cluelessness", rather than "incompetence", as it read on the version of the Wikipedia entry on Hanlon's Razor in the reference attributed to him:
From: J. Porter Clark (jpc-at-hammer.msfc.nasa.gov) Subject: Re: alt.ntia.* -- boy, the government still doesn't get it Newsgroups: alt.config, news.admin.misc Date: 1994-11-16 19:01:29 PST
texmex-at-Starbase.NeoSoft.COM (Steve Patlan) writes:
In article <3absu3$od5-at-hammer.msfc.nasa.gov>, J. Porter Clark wrote: >
I didn't even know that there was a govt.* (or gov.*) hierarchy. Is there? You tell *us, meester government man.
I was originally tempted to write, "There is no govt.* or gov.* hierarchy, and I know because I work for Uncle Sam," but, hey, maybe there is one out there. They don't tell me everything. I don't know where the UFO's are stored. 8-)
I cannot determine whether the NTIA was trying to deliberately run roughshod over the USENET community or whether they were merely ignorant of the way things are supposed to be done. They were apologetic and seemed sincere, but sufficiently advanced cluelessness is indistinguishable from malice. 8-)
No real opinions here, so I won't even charge two cents this time.
J. Porter Clark jpc-at-hammer.msfc.nasa.gov or porter.clark-at-msfc.nasa.gov NASA/MSFC Flight Data Systems Branch "Do not read this manual." - SunSoft WABI manual