What is a crime?

I recently had an interesting discussion about what should be considered a crime and what not. Lies - should they be illegal? I say no. What about fraud? I say yes. There is a significant difference in nature between a lie and fraud. If I call myself the most attractive, well-spoken man in the world, I could be telling a lie, and sure enough that would be easy to prove to some chosen jury of 12 people. But I have committed no crime. If I tell everyone my neighbor is a child-molester I have committed no crime although I could not back up my case with evidence. At best I have injured my own reputation among those who heard my accusations, asked for evidence and received none.

A thought worthy quote:

If I take but a single cent of a man's property, without his consent, the act is a crime. But if two men, who are compos mentis, possessed of reasonable discretion to judge of the nature and probable results of their act, sit down together, and each voluntarily stakes his money against the money of another, on the turn of a die, and one of them loses his whole estate (however large that may be), it is no crime, but only a vice. (#)

If there is any role for man-made laws, created by a man-made State, then it is to protect individuals from physical attacks and theft or manipulation of their physical property. A lie does not fall within these borders. A moral or ethical code of law has no place within the State-apparatus. If I tell you that a house is safe and you move into it without any further checking of its structural capacity, and the house falls to the ground one week later, I committed no crime. But if I bribe a house-inspector to give the house the thumbs up, and sell the house on the notion that it has been checked for faults against collapse, then the simple lie turns into fraud, and a crime has emerged. Yes, even if the house does stay up.