The paper argues first for the immense importance of the question whetherwe possess free will for philosophical anthropology, ethics, penal law, andreligion, showing that the personhood of man is incompatible with a negationof his free will. It proceeds by discussing briefly the essence and levels offree will, showing that free will is an irreducible archdatum (urphenomenon)that in spite of its indefinability allows for an analysis and unfolding of itsessential qualities. The paper then distinguishes the different dimensionsof human free will as cause of action and intentional response to goods andvalues, and discusses their relation to morality. It then shows that the centralphenomena of “cooperative freedom” and of the “gift of self” are the supremefulfillment of persons. Lastly, different arguments for the actual existenceof human freedom are explored: a) an argument from the immediateevidence of freedom in the cogito; b) from the evidence of “eternal truths”or “necessary and supremely intelligible essences” about free will; c) fromthe experience of moral calls and oughts; d) from the undeniability of freewill without contradiction; and e) from the experience of acts whose objects(persons and their acts) presuppose free will. Through these “five ways” theevidence that we do indeed possess free will can be attained.