Chapter 10 Believing What We Want—A New Doxastic Voluntarism

One of the philosophically most interesting developments in the wake of the probabilism debate was the conception of new forms of doxastic voluntarism. Doxastic voluntarism, in a crude summary, proclaims that human beings can decide at will what they believe. In its most radical understanding, which in­ cludes the power to believe absurdities at command, doxastic voluntarism has never been part of the scholastic tradition. However, scholastics assigned a sig­ nificant role to the will with respect to the generation of beliefs or opinions. The will can indirectly maneuver us towards beliefs or opinions by directing our attention to this or that piece of information, thus causing a selective in­ take of information. Scholastics also assumed that a person, or respectively her will, can decide whether to pass or suspend judgment, at least in cases of not epistemically certain cognition. And they claimed that the will can strengthen our beliefs, so that they become subjectively certain and unwaver­ ing. For most, if not all scholastic authors, this did not suffice to render it psy­ chologically possible to assent to less probable propositions (that is, hold them to be true).1 This possibility became central for the evolution of probabilism, because moderate probabilists accepted the assumption that probable propo­ sitions must be assertable by competent and reasonable persons. Hence, to be truly probable, less probable propositions needed to be reasonably assertable. To combine reasonable assertability and probabilism, new forms of doxastic voluntarism, which surpassed their medieval ancestors in radicality but also in sophistication, were conceived in the second half of the seventeenth century. The present chapter will outline this process, but discuss the details of proba­ bilist doxastic voluntarism with primarily one author in mind: Anthony Terill (1621–1676), about whom more will be said in Section 3. Terill conceived the (in my opinion) philosophically and psychologically most sophisticated version

1 Nicolas Faucher claims that some medieval scholastics, such as Alexander of Hales and Pierre Olivi, assumed a direct doxastic voluntarism of assent to less probable propositions (see Faucher 2015). Even if this is the case, and the issue depends on how one conceptual­ izes medieval doxastic voluntarism, Thomists, Scotists, and Nominalists would have rejected a direct doxastic voluntarism of assent. Thus, all the major sources used by early modern scholastics when discussing the interplay of intellect and will subscribed to an impossibility to directly assent to less probable propositions.

© koninklijke brill nv, leiden, 2019 | doi:10.1163/9789004398917_012 Believing What We Want—A New Doxastic Voluntarism 369 of scholastic doxastic voluntarism. Many contemporary observers concurred with this judgment. The Jesuit Superior General, Tirso Gonzalez (1624–1705), a staunch anti-probabilist, felt compelled to praise the subtlety of Terill’s ap­ proach, and the Catholic philosopher, Antonio Rosmini (1797–1855), singled out Terill in addition to Bartolomé de Medina as one of two authors who had inaugurated “a new scientific epoch” in Catholic moral theology.2 The basis for this estimation was Terill’s defense of doxastic voluntarism. He outlined why and how it can be possible and legitimate to change one’s own opinion to an­ other opinion, which the agent considered reasonably assertable by some well- informed other person, but less probable than her own opinion. In modern philosophical terminology, persons who are equally informed, competent, and reasonable are called epistemic peers. Terill thus claimed that we may, without irrationality, move to adopt the opinion of a reasonable epistemic peer, even if we regard it as epistemically less justified than our still incumbent own opin­ ion. On this basis, the representative of a scholastic school of thought, such as Scotism, could convert to Thomism, or to use modern examples, a Kantian could become a utilitarian, or a Protestant a Catholic for practical rather than epistemic reasons. Moreover, Terill assumed that this can be achieved by an act of the will. These claims resonate with a modern debate on doxastic volun­ tarism, which gained ground in the last half century, and which I will refer to repeatedly in this chapter, not least to probe the lasting philosophical signifi­ cance of Terill’s views.

1 Scholastic Doxastic Voluntarism before the Seventeenth Century

The possibility of assenting to less probable propositions, that is, to hold them to be true or to believe them, initially did not pose a problem for probabilism. As discussed in Chapter 2, Juan de Salas (1553–1612), one of the most eminent early probabilists, recognized that making such an assumption would lead to epistemological difficulties. He therefore emphasized that probabilism was first and foremost about acting in accordance with less probable propositions, and

2 See Gonzalez (1694), diss. 1, n. 24: “Inter defensores sententiae benignae de usu licito opini­ onis minus probabilis, & minus tutae omnium acerrimus & copiosissimus est P. Antonius Terillus”; Camargo (1702), pars I, lib. 1, contr. 5, a. 7, n. 70; Concina (1751), lib. 3, diss. 2, cap. 3: “Princeps Probabilismi reflexi est P. Antonius Terillus, vir sane acuti ingenii”; and Rosmini (2011: 262): “It is not surprising that such progress produced a kind of moral-scientific crisis in mankind, so that the names MEDINA and TIRILLO ought to stand in any philosophical history of moral sciences as marking the beginning of a new scientific epoch”. In Italy, Terill was often called Tirillo.