|The divine comedy|
Last Thursdayism (alternately Last Tuesdayism or Last Wednesdayism) is the idea that the universe was created last Thursday, but with the physical appearance of being billions of years old. Under Last Thursdayism, memories, books, fossils, light already on the way from distant stars, and literally everything was all formed at the time of creation (last Thursday) in a state that causes them to appear to be older.
Last Thursdayism functions both as philosophical point about how our observations may not match with "reality" and a reductio ad absurdum of the young-Earth creationist idea of omphalism: if the world was created 6000 years ago with the appearance of being made billions of years ago, what is there to stop us from claiming it was made Last Thursday?
The debate on whether Last Thursdayism is true has raged on ever since
the creation of the universe on Last Thursday its inception.
“”Last Thursdayism is false because I clearly remember events from before Last Thursday. It does not follow that God could have fixed our minds and experiences to make us think we only felt things before last Thursday. For example I have a note with the date on it, "Wednesday, July 15, 2009." This would not be possible if the world was created on "Thursday July 16, 2009."
Yet if God placed your memories of events before Last Thursday into your mind, then it would appear as if you remembered something "before" Last Thursday. Because Last Thursdayism can explain anything, it operates as an unfalsifiable hypothesis (much like the omphalos hypothesis).
 Occam's Razor
Last Thursdayism (and any similar idea) can be seen as "hyperomphalisms", extreme forms of omphalist doctrine designed to show the absurdity of it. As such they constitute a skeptical hypothesis of the very existence of past, not just events that occur within it.
However, the assumption that all of the universe was specially created is unnecessarily complex, when the actual universe appears to be really old; it thus makes more sense, via Occam's Razor, to assume uniformitarianism and an old universe.
Bertrand Russell explains the problems with proving that the universe was created, intact, at a set point in the past in his "five minute hypothesis":
“”There is no logical impossibility in the hypothesis that the world sprang into being five minutes ago, exactly as it then was, with a population that "remembered" a wholly unreal past. There is no logically necessary connection between events at different times; therefore nothing that is happening now or will happen in the future can disprove the hypothesis that the world began five minutes ago.
|—Bertrand Russell, The Analysis of Mind, 1921, pp. 159–60) |
A recent manifestation of Last Thursdayism appeared on the USENET group talk.origins in 1991, as a hyperbolic response to omphalism. It gradually gained popularity, and on August 25, 1996 the FAQ  for the Church (its Catechism) was posted to talk.origins by Michael Keane. It is similar to Unicornism or Pastafarianism, and claims that the universe was created Last Thursday by "Queen Maeve the Housecat", who on Next Thursday (Judgment Day) will admit those who were nice to cats to Paradise and damn the unkind, the uncaring, and Creationists to the never-cleaned Eternal Litterbox. Since then the website for Last Thursdayism has become defunct.
It should be noted that in some circles, especially talk.origins, Last Tuesdayism is taken as a schism of Last Thursdayism and is founded on the belief that the world was created last Tuesday but that unlike last Thursdayism, this happens every Tuesday.
 See also
- Mirror of the defunct The Church Of Last Thursdayism's webpage (stored at www.archive.org)
- Archived Usenet Post containing the FAQ of the Church of Last Thursdayism (stored by Google.com)
- Study: All Of Your Memories Implanted In You 5 Minutes Ago When Universe Was Created
- ↑ Freethought and Rationalism discussion board - post 6021616
- ↑ http://www.theinfidels.org/zunb-bertrandtrussell.htm
- ↑ Church of Last Thursday FAQ author=Micheal Keane date=1996-08-25 newsgroup=talk.origins http://groups.google.com/group/talk.origins/browse_thread/thread/9263b3be16d586f3 accessdate= 2007-10-08
- ↑ The Church of Last Thursday