Aquinas believed that the reality of friendship is conditional on the friend's will because friendship requires some conformity of wills between the friends. This chapter considers two different sources of the uncertainty that, according to Aquinas, surrounds the operations of others' wills: (1) The human heart cannot be scrutinized by other human beings; (2) We have no certain knowledge of future singular contingents. Future operations of others' wills are singular and contingent. This chapter has two sections. Section 5.1 discusses the presumption of authenticity as a possible device to overcome the problem posed by uncertainty about others' present wills. Section 5.2 discusses hope as an aid to overcome the problem posed by uncertainty about others' future wills. Both sections also explore the relationships between self-love and self-assessment that are presupposed by hope and the presumption of authenticity. It is argued that for Aquinas, in the absence of evidence to the contrary, we should presume that other persons' communicational acts reflect their will. He also thinks that hope, in being an aid to the motion of the will, reduces the uncertainty surrounding the attainment of one's goal. Both the presumption of authenticity and the habit of hope presuppose a certain degree of modesty.
Keywords: present wills, future wills, authenticity, hope, pride, modesty