A "clean slate" is, idiomatically, a fresh start or restart at anything. It is most often used after someone has made a major mistake - a person who has just been released from prison has been given a clean slate; another example might be a significant other who has been forgiven for cheating.
The etymology of the phrase is not particularly difficult. John Locke famously created his idea of the "tabula rasa", Latin for "blank slate", in his Essay Concerning Human Understanding. In it, he explains that we as humans are not born with any particular ideas or beliefs, but rather we gain them through our experience in the world. With this idea comes the corollary that at any time, if we were to drop our beliefs, we could again be a clean slate and learn ourselves anew.
Clean Slate is also the name of a 1994 Dana Carvey film. In it, Carvey stars as a witness to a mob crime. There's only one problem: whenever he falls asleep, he forgets everything he ever knew. A full 7 years before Memento, this film explored the rarely used genre of memory loss to mediocre comic effect. The gags are all kind of weak, and as Carvey's first foray into a starring role (after his most excellent performance in Wayne's World) it was definitely beneath his talents.
Carvey and not-quite-as-dead-as-advertised love interest Valeria Golino (Hot Shots, Rainman) spend most of their time trying to remember where he's supposed to be - which is funny the first time when the audience doesn't know, either, but quickly loses its charm the fourth time you're yelling at the screen, "The courthouse! You're supposed to be at the courthouse!" A few running gags throughout the picture simply don't cut it, and the main character is certainly not as engaging as the larger-than-life Garth. Still, the movie does have one major highlight: James Earl Jones cracking wise with that no-nonsense voice of his is music to my ears.
My Rating: 5 out of 10. Catch it on late night cable.
Clean Slate is also the name of a security program made by
Fortres Grand Corporation. It is used on computers which multiple users frequently access. Essentially what it does is erases all personal information (saved passwords, cookies, and files) when the computer logs out or reboots. Of course, security experts will warn you that nothing is ever completely gone, but for the most part, Clean Slate appears to have the thumbs up for its effectiveness and competency. Obviously, its most popular users are schools and libraries, and if you happen to work for one of these administrations, or happen to need such a scrubber, you can learn more about the program by visiting
http://www.fortres.com/products/cleanslate.htm.