Presumption of culpable mental state requires the accused to rebut it; factual proof must satisfy beyond reasonable doubt. A statutory presumption requires the court to assume the accused possessed the requisite culpable mental state (including intention, motive, knowledge, belief, or reason to believe) in prosecutions under the Income-tax Act for offences requiring such an element, while allowing the accused a defence to prove absence of that mental state. The section also mandates that facts are proved only when the court is satisfied beyond reasonable doubt, not by mere preponderance of probability.