Presentation for the upcoming XVth international congress of the SIEPM, Paris 22-26 August 2022.
Thomas sets out his five ways (ST Ia Q.2, A.3) after rejecting several ‘a priori’ arguments for the existence of God (ST Ia Q.2, A.1), most notably among them his account of Anselm’s argument. The difference is usually accounted for by his shift from an Augustinian to an Aristotelian epistemology. This paper is a critical philosophical discussion of his rejection of these a priori arguments.
Both in his main reply to the a priori arguments, and in his reply to the third a priori argument, he distinguishes between what is knowable, and what is knowable for us. But especially in his reply to the third a priori argument – the argument from truth as arguably found in Bonaventure, but dating back to Augustine – this is arguably problematic. That argument states that God’s existence is self-evident, since God is truth and any denial of truth implies a contradiction. Aquinas replies to this by stating that the existence of truth in general is self-evident, but not the existence of a first truth. But the transcendent nature of truth implies a transcendental dimension of the argument on which it explicitly relies, that is not taken into account in Aquinas’s answer.
Both the argument and Aquinas’s answer shift to a meta-level to discuss truth itself, but the argument relies on the transcendental dynamic at work in such a shift since the transcendence of truth implies that it applies across all language levels, and derives a substantial conclusion from that. Aquinas rejects this by claiming that “non est per se notum quoad nos” that there is a first truth. However, this claim instantiates a meta-level from which a property of truth is discussed which can either be warranted or rejected, implying the knowability of the truth claims made on this meta-level. Any further discussions would only instantiate further meta-levels, or eventually have to accept a first truth as that truth ‘higher than which nothing can be thought’.
Although Anselm starts from goodness in chapter one of his Monologion, in chapter 18 he clearly recognizes this transcendental dynamic of truth, which he also takes up again in De Veritate. Hence, the ‘argument from truth’ as developed above arguably forms part and parcel of the ‘unum argumentum’ as he presents it in chapter 2 of his Proslogion. Moreover, it would give a stronger reading to the version of the argument in chapter 3, reading it along the lines of the argument from truth. Given that interpretation of Anselm’s argument, the same transcendental dynamic can be applied to Aquinas’s main reply on the unknowability of God for us, as well as his proper reply to Anselm’s argument.