Wiki is the Perpetual Now.
We start with a metaphor for what we're trying to accomplish. An idea, the expression of an idea, a product, some faintly perceivable Utopian vision. Whatever.
We discuss it, hack at it, take cracks at it, build it up, tear it down, RefactorMercilessly, and always do so without fear. Along comes Teenie Meenie Bopper, 14 year old Wunderkind, to blow away a large portion of the content. Gone. Oh, well.
What have we really lost? We have lost an expression of the idea, but the idea is still there, in our minds. We put it into words once; we can do that again. In fact, we may have since then learned something that helps us to express the idea better and more clearly. Be not afraid. Be very not afraid.
Of course, this works best for simple cases, and particularly well for concepts that can be simplified even further when expressed a second time. Writing is hard; re-writing is sometimes easier.
But it is probably a valid assumption that the more complicated parts of a Wiki page have been composed "off line" and the original is still on the author's system. So, if he or she thinks a precious contribution was lost, it may be not much work to recreate the page from such an external source. And, maybe, recreating the page also makes long pending updates available to the Wiki community.
Should the original author not care but many people liked the page, probably someone has made a copy, so accidental or malicious destruction can be fought easily. (Take this as an argument to make private copies of pages - or parts of pages - that are of real value to you. Or rather: copy parts of pages whenever the EXPRESSION of the idea is of more value than in the idea itself.)
As an example, step back a quarter of a century or more when someone wants to discuss the idea of file name extensions, i.e. tell something about the contents of a file as part of the file name itself. A Wiki page mentioning that idea could be easily recreated if it was lost, and most of the arguments in a discussion of the topic aren't probably of much interest after some time.
On the other hand take a Wiki page with an exhausting summary which file name extension is used for what. The IDEA behind such a page is that it would be useful to HAVE such a list as reference. But it would be a tremendous amount of work to recreate the full list, despite the fact the idea is simple. So, make a local copy in case the list is lost on the Wiki, or better yet, make the information available on a non-Wiki page.
If we contribute to a Wiki our primary motivation should be to SHARE and we should understand our contribution is actually a GIFT to the Wiki community. As with any gift, our input is given with no thought of compensation in return. Contributions -- gifts -- may be destroyed, misused, ignored, or derided.
Of course it may give us a nice feeling if our gift is welcomed and vice versa it may give us equivalently bad feelings if we find something we wrote only to survive a few hours. So, as civilized people, we are well advised if we consider the question "what if this were my own contribution" before changing something somebody else wrote.
Finally, there is of course a risk that it will drive away a number of "good" people when they find their contributions changed frequently, misused or even deleted, but the conclusion a Wiki therefore will become a playground for "violent children" has not proven true. Nevertheless, whenever you are about to turn away from a Wiki you should understand that no possible abuse of a page (its deletion included) removes a single iota of value from the original contribution itself. Wikizens continue to contribute despite the "risk" that their contributions will suffer whatever damage may be.
(And, maybe, the next time you open this page the last statement, or some paragraph, or even everything was changed to say the contrary of what I wrote, well that's the WikiWay ... -- MW)
It should also be noted here that the ever-present thread vs document discussion (ThreadModeConsideredHarmful, etc.) mostly doesn't address the value of following the evolution of a page. The preference of consensus seems to be reducing the cogent parts of a discussion to a pseudo tit-for-tat conversation between DramaticIdentities offering differing viewpoints. We all appreciate the WikiMasters here who have the capacity to reduce a long winded discussion down to a few paragraphs that contain the essence of the replaced intercourse. The word "however" is used to good effect in this context. The actual conclusions are left to the reader who must decide his own mind after having read the entire topic entry.
So what does this have to do with "The Perpetual Now"? Wiki is the essence of now. It is the short-term memory, the local heap, of the contributors. Agonizing over the WikiMindWipe is akin to agonizing over the fact that, in two years, you probably won't remember the phone number that you just got from directory assistance. The answer is the same in both cases: data that needs to belong to tomorrow deserves to be protected more than data that is in flux, in current discussion. Wiki is all about now.
(or about what was then now)
I think that the proximity or difference in the content of the page from NowPractices? is self-evidently time-diff with even the most superficial of reading. Practices have a now-ness to them if they are presently being used, otherwise one, if talking about or discussing Windows95 or MicrosoftDos6Point22, discover that now is never perpetual, rather it is relative. ThinkingOutLoud.DonaldNoyes.20121017)
Is it possible that the whole brunt of this discourse has escaped you, Donald? The long-winded speech given above has been massaged by many participants for well over a decade. The point is that Wiki is, in fact, perpetually now. ThreadMode preserves a record of ThingsOnWikisMind, but the point about the WikiGnome reduction to a discussion between DramaticIdentities is the final "nowness" of Wiki's existence -- that of thesis, antithesis, and synthesis being rolled into an ongoing discussion.
Help to keep Wiki in the perpetual now, folks. Participate in the discussion. Add when new or improved ideas come to light. Reduce when content is no longer relative. Organize when redundancy rears its ugly head. Delete when discussion dissolves into drivel.
Wiki is the Perpetual Now.