Alexander Pruss’s Principle of Sufficient Reason (PSR) states that every contingent true proposition has an explanation. Pruss thinks that he can plausibly maintain both his PSR and his account of libertarian free will. This is because his libertarianism has it that contingent true propositions reporting free choices are (virtually) self-explanatory. But I don’t think Pruss can plausibly maintain both his PSR and libertarianism without a rift occurring in one or the other. Similar to the old luck/randomness objection, I contend that Pruss’s libertarianism is susceptible to what I call “the inexplicability objection”, which attempts to show that agents’ free choices involve contingent brute facts. Pruss may be able to partially explain a proposition such that Jones freely chose A for reason R, but he cannot adequately explain a contrastive proposition such as that Jones freely chose A for R rather than B for R*. The result is that either PSR is too explanatorily permissive for libertarianism, or libertarianism is too explanatorily impermissive to satisfy PSR. After considering what I take to be Pruss’s best response to the inexplicability objection, I conclude that his attempt to reconcile PSR and libertarianism is unsuccessful.

亚历山大·普鲁斯（Alexander Pruss）的《充分理由原则》（PSR）指出，每个或有的真实命题都有一个解释。普鲁斯认为，他可以合理地维持自己的PSR和对自由主义者的自由意志的描述。这是因为他的自由主义者认为，报告自由选择的或有真实命题（实际上）是不言自明的。但是我不认为普鲁斯可以合理地维持他的PSR和自由主义，而不会在彼此之间产生裂痕。与旧的运气/随机性异议类似，我认为普鲁士的自由主义容易受到我所说的“莫名其妙异议”的影响，这试图表明代理人的自由选择涉及偶然的残酷事实。普鲁斯可以部分解释一个命题，以便琼斯出于原因R自由选择A ，但是他不能充分解释一个相反的命题，例如琼斯自由地选择A代替R而不是B代替R *。结果是，要么PSR对自由主义来说太宽容，要么对自由主义者来说，对PSR来说太宽容了。在考虑了普鲁斯对莫名其妙的异议的最佳回应之后，我得出结论，他调和PSR和自由主义的尝试是不成功的。