Since his rediscovery by Alwin Plantinga in the 1970s, the possibility of counterfactuals of freedom in Molinism has become one of the main issues in the contemporary analytic philosophy of religion. Notwithstanding this, Luis de Molina (1535-1600) remains one of the most influential and least known authors of late scholasticism and early modern philosophy. The papers collected in this volume treat the whole range of issues posed by his metaphysics as set out in his revolutionary "Concordia" and in his practical philosophy - especially concerning law and economics - in his groundbreaking work "De Justitia et Jure". They also examine Molina's historical commitments and his influences on philosophy. In this way this Companion offers the first comprehensive and thorough overview of Molina's thought.