Possibly the best-known quote from the works of Dostoevsky is this:

"If God does not exist, everything is permitted."

You can see it, for example, on the title page of the self-designated "Dostoevsky Resource on the Net" by Christiaan Stange; and again in the Quotes section of Lu's Greco's Dostoevsky page; and yet again (possibly lifted intact from Stange's page) on Luba Petersen's Dostoevsky site.

This soundbite sentence has propagated widely into popular religious debate on the internet. Like any good soundbite, it neatly encapsulates the fears and hopes of a diverse audience: the believer's fear of, and the nonbeliever's hope for, a secular moral system.

There is only problem with this well-known quote:

Dostoevsky never wrote it!

I say this with confidence because I have searched the online text of the Constance Garnett translation of The Brothers Karamazov, examining every use of "God" and "exist" and "lawful" ("lawful" is how Garnett translates the word that others translate as "permitted").

The sentence does not appear, nor anything close to it. Nor does it appear in any of the other four Dostoevsky novels whose complete English texts are available online. The fact that a nonexistent text can be widely attributed to a famous author reveals the limitations of precomputer scholarship. The fact that I could so quickly prove it erroneous highlights the opportunities for modern scholars.

(http://www.autoadmit.com/thread.php?thread_id=1957470&forum_id=2#20774210)

Ivan is what they aspire to be.

Alyosha is what they ought to be (except quotemos -- that scum will always be Smerdyakov).

(http://www.autoadmit.com/thread.php?thread_id=1957470&forum_id=2#38602913)

How is this even a question, the author spells it out pretty clearly

(http://www.autoadmit.com/thread.php?thread_id=1957470&forum_id=2#38603165)