Thomistic Existentialism and Cosmological Reasoning, John F. X.Knasas, The Catholic University of America Press, 2019 (ISBN 978‐0‐8132‐3185‐3), xiv + 330 pp., hb $65

Abstract

John F. X. Knasas is currently the most important proponent, in the lineage of Joseph Owens and Étienne Gilson, of what is called ‘Existential Thomism’ or ‘Thomistic Existentialism’, directed by interpretation of the centrality of the notion of being (esse) in Thomas Aquinas' metaphysics (pp. 2–3). In Thomistic Existentialism and Cosmological Reasoning, Knasas magisterially argues not only that this school of Thomism accurately represents Aquinas' own thought but also that it renders accessible a concept of esse that so augments the ability of theistic argumentation, specifically that designated ‘cosmological’, as to escape commonly encountered criticisms of natural theology (p. 314). Knasas considers as ‘classical’ that species of cosmological argumentation championed by Gottfried Wilhelm Leibniz, since it was so classified by Immanuel Kant, with whom the designation originated (pp. 1, 10–13). But in Knasas' judgment, this classical argumentation is indeed vulnerable to Kant's critique, for it depends on that erroneous assumption of ‘the ontological argument’ that ‘existence’ (esse) is predicable of a subject: ‘existence’, Knasas agrees, ‘is not a predicate’, but asserted (or not) of a subject with whatsoever it is predicated (pp. 18–19, 25–26). However, Knasas criticizes as unacceptably deficient the notion that esse is merely indicative of the ‘fact’ of a being, which, he suggests, has been assumed by Leibniz and Kant in particular, but also by a multitude of ancient and modern philosophers in general (p. 34). To illustrate how Aquinas was able to philosophically justify his own concept of esse in the context of theistic proof, Knasas focuses on Aquinas' early text On Being and Essence (p. 31). Therein, he argues, Aquinas reasoned from accounts of composite beings, which have esse distinct from their essence (not merely as an indication of their ‘facticity’ but as the very ‘act’ whereby they are), to an account of pure and simple esse, which is itself subsistent (pp. 32, 58). In Knasas' analysis, Aquinas' statement that one ‘can know what a man or a phoenix is and still be ignorant whether it has being [esse] in reality’ signals the intellect's power to consider an essence absolutely, that is, as distinct from the esse whereby it is, and thus ‘as existence-neutral’ in reality (pp. 38, 41, 49). Naturally, one may imagine any variety of essences, even those which have only ever had ‘cognitional existence’, such as of the sphinx or the chimera, or those which are of entirely immaterial beings, such as angels, with ‘real […] existence’ (p. 51). But, in accordance with Aquinas' ‘sense realism’, naturally any such essence may only be found in the human intellect in virtue of an essence with real existence that produces a material being that enters the senses as a phantasm, whereupon it undergoes the ‘twofold operation the intellect’ that sequentially abstracts the phantasm as an esse-neutral intellectual species and judges that species to have been abstracted from a phantasm that is but a material being received into the senses (pp. 39–46, 144). Knasas aptly recognizes this operation as ‘the mental furnace’ of ‘metaphysical ideas’, for it is only thus that one is able to reason to the aforementioned fantastical or spiritual essences, and judge whether their esse or non-esse is knowable (p. 102). However, this also seems to be the only means by which one may naturally know esse. Thus does Knasas follow Aquinas' course of reason from that which is essentially esse-neutral to an essentially pure and simple subsistent esse (pp. 59–63). The course of reason in On Being ‘enables the metaphysician to quickly reach esse subsistens [subsistent esse] as the only adequate cause of [common] esse’ had by every other substance and even every accident insomuch each is (pp. 4, 216). But Knasas maintains that this course of reason is the common motor that moves a reader through each of Aquinas' wended ways from different creatures to their singular Creator (pp. 5, 173, 216). ‘If the priority of esse’ in the essence ‘is focused upon’, in which case the motor is bare as in the Summa theologiae's second way, ‘then the shortest path opens’, which very approximately resembles the course of reason in On Being (pp. 216, 256–259). But ‘[i]f the focus is esse’s character as the act' of the essence, by which the motor is ‘camouflaged’ in ‘a more robust’ even if less rudimentary ‘version’ of that course of reason as in the case of the Summa's third way, ‘then a much longer path […] opens’ (pp. 4–5, 216, 259–265). Importantly, however, Knasas notes that even ‘[a]t each point of the second path, […] the priority of some esse is wanting to be focused upon’, such that ‘the metaphysician need not walk the entire length of the second path to its conclusion of esse subsistens’, for any esse-neutral essence that happens to have esse ‘permits immediate reduction […] to subsistent existence’ (p. 216). Granted, Aquinas' course of reason may seem ‘similar’ to that of Leibniz, but, in Knasas' estimation, the former's attention to esse plunges the comparably superficial thought of the latter into a far profounder recognition of the common esse of essences, which itself reduces to subsistent esse, so as to constitute the motor of each of Aquinas' theistic proofs in a manner that escapes ‘the standard objections’ to classical cosmological argumentation, especially ‘Kant's insistence that existence is not a predicate’, for ‘[n]one of this treads on ontological reasoning’ (pp. 2, 32, 68–69, 131–169, 289). One may regret that Thomistic Existentialism and Cosmological Reasoning presents common and subsistent esse absent further illustration of their difference, which is achievable by investigation into conceptual remotion and analogical language. Furthermore, the book is in want of stronger defense of the interpretation of the course of reason in On Being against some admitted challenges, most notably that of Martin Heidegger's critique of ‘ontotheology’ (pp. 161–169). Further still, because many theistic proofs in the Thomistic corpus are quite similar, the book might have best revealed their dependency upon the On Being course of reason not per instance of proof but per kind of instance of proof, which would permit less laborious treatment of more such proofs in the Thomistic corpus (pp. 216–289). However, despite these few criticisms, Knasas' book is of great value to contemporary philosophical discourse, not only for what it accomplishes, to wit, advance in, and defense of, Existential Thomism in application to natural theology, but also for what it prompts to be accomplished by further venture in Existential Thomism, such as its thorough phenomenological establishment, so as to render the immense philosophical wealth of Aquinas' concept of esse even more appreciable for those sensitive to the so-called end of metaphysics than Transcendental Thomism has yet been able to afford (cf. pp. 39, 105, 143, 313–314). Open access publishing facilitated by Australian Catholic University, as part of the Wiley - Australian Catholic University agreement via the Council of Australian University Librarians.