Nihilism is to Thomism (thus, Catholicism) as Satan is to the court of angels in the Book of Job.
There is an inter-meshing between these contradictory points that rests on logical inference. We might say it as this: Certain nihilist propositions are correct as conditionals; however, being conditionals shows that the contrary conclusion to Nihilism is true.
For a common example through Job, God and Satan essentially wager on this: Satan posits that any man, if taken far enough, will break. A contemporary idiom would be “every man has their price.” Is the proposition true? Per Aquinas, it is (Summa, Q. 109). No man can resist sin for long, without grace; every man has a breaking point without God’s grace.
Now some of you may know that I was once a Nihilist. Even with my Nihilistic mindset, I found Thomism attractive and appealing. Not only could it solve the problems of Nihilism, Thomism did so from Nihilism’s own grounds (both belong to the Western Metaphysical Tradition, after all). Namely, as a Thomist and as a Nihilist, I found grounds on which both agreed: Where they differed was on whether the conditionals and inferences were true or not. Indeed, as a Nihilist, I found that Thomism provided far better clarity on Nihilism itself than Nihilists did.
With that in mind, I am not here to make a case for Nihilism, but to draw those who, like I once did, find Nihilism to be true away from it by showing the contrary logical inference; likewise, it would also be able to make a case against Atheism (a kind of Pascalian argument), since it has no safeguards against some of the following propositions (and at times, even embraces them), and that the logical conclusion of Atheism is Nihilism:
If there is no God, then there is no human nature (Sartre; ‘Existence precedes Essence’); however, there is human nature, therefore there is a God (Summa Q. 93).
Life possesses meaning insofar as Man’s actions aim toward an end which is the good (Summa).
Life has no meaning, for there is no real ‘good’ to be aimed at, and with which our end is death, which is opposed to any form of ‘the good’ (General Nihilism).
We are imprisoned in ‘nothingness’ (Heidegger).
We are imprisoned by ‘nothingness’ insofar as creatures are considered ‘dark’ insofar as they are from nothing [viz., ex nihilo] (Quaestiones disputatae de Veritas, Aquinas, reply to objection 5).
The proper movement of a being that stems from nothingness is to tend toward nothingness; however, [a being that has] nature has a tendency towards the good, which is the same as being, therefore the proper movement of a being is to existence (Quaestiones disputate de Potentia, Objection 16 and reply to objection 16).
There is no such thing as Love, i.e., Charity, for all actions as such derive from some ulterior motive (General Cynicism).
Only through God can Man come to possess Charity; for Charity is a virtue that surpasses Man’s natural limitations (Summa); likewise, certain actions such as almsdeeds only flow forth through Charity properly, wherein Charitable actions possess materially the virtue of Charity, but not formally, such that these actions proceed from a different source [‘ulterior motive’] of either natural light [‘reason’], fear, or gain (Summa, reply to objection 1).
There is no such thing as morality, for there is no such thing as good and evil, and there is no such thing as good and evil for there is no objective measurement of rule [viz., nature], and all things listed as such are subjective and belong only in reference to those respective references, viz., the measurement of good and evil is respective to each being only (General Nihilism).
The measurement of rule is established through one’s nature, by which when one acts in accordance with it, one acts good, and when one acts against it, one acts in an evil manner (Summa).