This paper describes a logical machineryfor computing decisions based on an ATMSprocedure, wherethe available knowledgeon the state of the world is describedbya possibilistic propositionallogic base(i.e., a collectionof logical statementsassociatedwithqualitative certainty levels). Thepreferencesof the userare also describedbyanotherpossibilistic logic basewhose formulaweightsare interpreted in termsof priorities and formulasexpressgoals. Twoattitudes are allowed for the decisionmaker:a pessimisticuncertainty-averse one and an optimistic one. Thecomputeddecisions are in agreementwitha qualitative counterpartto classical expectedutility theoryfor decisionunderuncertainty.