This chapter focuses on the freedom of the will and the concept of a person. Many animals appear to have the capacity for "first-order desires" or "desires of the first order," which are desires to do or not do one thing or another. It is hardly sufficient to formulate the distinction between first-order and second-order desires. There is a close relationship between the capacity for forming second-order volitions and another capacity that is essential to persons—one that has often been considered a distinguishing mark of the human condition. It is only because a person has volitions of the second order that he was capable both of enjoying and of lacking freedom of the will. It is in securing the conformity of his will to his second-order volitions, then, that a person exercises freedom of the will. And it is in the discrepancy between his will and his second-order volitions that a person who does not have this freedom feels its lack.