According to Snopes.com:

We've been seeing this "quote" on the Internet since December 2001, sometimes attributed to Julius Caesar, sometimes to William Shakespeare (presumably lifted from his play, Julius Caesar). Throughout the summer of 2002 it gained popularity, appearing in countless posts to newsgroups and even surfacing in various letters to editors in a handful of newspapers.

Its popularity is not hard to understand: The USA has been embroiled in a war against terrorism far across the world and is contemplating war with Iraq, and the latter action, especially, has been the subject of much debate and dissension within America. This telling observation from Caesar appears to offer yet another valid reason for not yelling "Our leader; right or wrong!" and blindly following the President into war. It is therefore a favorite of those who'd rather sit this dance out, thankyouverymuch.

Yet as popular as the quote is, it's not real. These words are not anything Julius Caesar ever wrote or said. No biographies of Caesar or histories of Rome contain these lines, and scholars who have made it their business to know everything about the man draw a blank on this quote. Likewise, Shakespeare did not stuff this soliloquy into the mouth of the title character in his play Julius Caesar, nor did any of the Bard's other characters utter it. No record of this quote has been found prior to its appearance on the Internet in late 2001.

So what's going on here, then?

As Ralph Keyes explains in Nice Guys Finish Seventh, his compendium of misattributed and false quotes, "Famous dead people make excellent comentators on current events." The dead do not reappear to challenge words assigned to them, an attribute much prized by those looking for convenient spokesmen to lend authority to their convictions. This "quote" called for a strong and respected military leader and statesman, hence Caesar was resurrected to give it voice.

Barbara "great Caesar's ghost!" Mikkelson