I. A person is guilty of murder, a felony, or a misdemeanor only if he acts purposely, knowingly, recklessly or negligently, as the law may require, with respect to each material element of the offense. He may be guilty of a violation without regard to such culpability. When the law defining an offense prescribes the kind of culpability that is sufficient for its commission, without distinguishing among the material elements thereof, such culpability shall apply to all the material elements, unless a contrary purpose plainly appears.
II. The following are culpable mental states:
(a) "Purposely." A person acts purposely with respect to a material element of an offense when his conscious object is to cause the result or engage in the conduct that comprises the element.