Truthmaking without necessitation

I propose an account truthmaking that provides truthmakers for negative truths. The account replaces Truthmaker Necessitarianism with a "Duplication Principle", according to which a suitable entity T is a truthmaker for a proposition p just in case the existence of an appropriate counterpart of T entails the truth of p, where the counterpart relation is cashed out in terms of qualitative duplication. My account captures an intuitive notion of truthmakers as "things the way they are", validates two appealing principles about entailment and containment proposed by David Armstrong, and invalidates the controversial Disjunction Thesis.