 Suppose that propositions exist necessarily. It is plausible to say that propositions can be freely negated, conjoined and disjoined to other propositions. On that view, there are operations of negation, conjunction and disjunction of facts which obey the principles we previously introduced. The resulting view is thus extremely strong. If not all propositions exist necessarily, then questions related to the Boolean operations receive answers which may vary according to the existence-conditions which are imposed on propositions.