Intent, Specific & General
The terms specific intent and general intent are traditional solutions to the very difficult problem of applying mens rea to specific criminal acts. Some instances of crime require very little intent, while others require a great deal. Perjury, for example, requires that the defendant specifically intended to lie after taking an oath that he would tell the truth, while sexual offense might simply mean that the defendant unwittingly and negligently acted in a way that was offensive.
The concept of specific intent is relatively simple. It usually refers to a specific state of mind that intended a specific, criminal result. For example, most first degree murder is defined by the specific intent to kill. Sometimes specific intent is also applied to the intent to cause harm beyond what was accomplished, for example, assault with intent to kill.
General intent is a much more abstract concept, one difficult to put a finger on. Sometimes not much more than the post facto justification of a sentencing, it is meant to signify that the defendant placed himself in a general state of mind to incur criminal liability and, in this state of mind, committed a criminal offense.
For example, let's say that Greg voluntarily gets drunk at a bar and kills Ted. Greg has never met Ted before, and witnesses say that Ted was heavily insulting Greg; furthermore, Greg is so drunk that he has absolutely no memory of these events, and appeared to have very little control over his body. Nevertheless, Greg somehow manages to put Ted's head through a window, which results in Ted bleeding to death. Greg is clearly not guilty of first degree murder, but neither is he innocent of Ted's death. He will probably be found guilty of negligent homicide, because his voluntary state of intoxication placed him in a generally culpable mental state in which "general intent" satisfies the mens rea requirement. In a less extreme example, if Beth, a diabetic, gets behind the wheel of a vehicle when she knows her blood-sugar is low, suffers an acute attack of hypoglycemia, losses control of her vehicle, and hits a pedestrian, she will probably incur criminal liability. Even though she was not in control of the vehicle, she voluntarily got behind the wheel when she knew she was in danger of losing control, thus satisfying the mens rea requirement in that she possessed a "general intent" to commit the crime.