Are all God’s activities identical to God? If not, which are identical to God and which not? Although it is seldom noticed, the texts of Aquinas (at least on the surface) suggest conflicting answers to these questions, giving rise to a diversity of opinion among interpreters of Aquinas. In this paper, we draw attention to this conflict and offer what we believe to be the strongest textual and speculative support for and against each of the main answers to these questions.

In this paper, the authors show that there is a reading of St. Anselm’s ontological argument in Proslogium II that is logically valid (the premises entail the conclusion). This reading takes Anselm’s use of the definite description “that than which nothing greater can be conceived” seriously. Consider a first-order language and logic in which definite descriptions are genuine terms, and in which the quantified sentence “there is an x such that…” does not imply “x exists”. Then, using an ordinary logic of descriptions and a connected greater-than relation, God’s existence logically follows from the claims: (a) there is a conceivable thing than which nothing greater is conceivable, and (b) if x does not exist, something greater than x can be conceived. To deny the conclusion, one must deny one of the premises. However, the argument involves no modal inferences and, interestingly, Descartes’ ontological argument can be derived from it.

Receptive potencies are the essence in relation to the act of being (esse) and the matter in relation to the form. Suárez identifies the essence with the existence. A potential essence, according to Suarez, is nothing; therefore it cannot be receptive potency for being (esse). The actuality of an actual essence is its being (esse). Hence, the actual essence does not need to receive any further being distinct from it. Essence does not differ really from being (esse); nevertheless, we can conceive it without being. Essence as “whatness”, quiddity, is closely connected with concept and definition. In this regard we may make some critical remarks on Suarez’s doctrine: If the “whatness” is identical to the being (esse), this fact has to be reflected in the adequate notion of the “whatness”. If it is so, it seems that the essence conceived without being (esse) is not the same essence any more. Furthermore: If essence and existence are identified, what is it to which existence can be non-trivially ascribed? What is the receptive potency for being (esse)? Arriaga follows Suárez in the doctrine of essence and being, in his teaching on the prime matter however he goes even further. Whereas Suárez ascribes to the prime matter its own actuality, Arriaga assigns to it some attributes of substance. In contradistinction to the Suarezian conception of receptive potencies, the Thomistic doctrine of the relation of participation between potency and act permits metaphysics to withstand the threats of mechanicism and the post-fregean trivialization of the notion of being (esse).

The authors evaluate the soundness of the ontological argument they developed in their 1991 paper. They focus on Anselm’s first premise, which asserts that there is a conceivable thing than which nothing greater can be conceived. After casting doubt on the argument Anselm uses in support of this premise, the authors show that there is a formal reading on which it is true. Such a reading can be used in a sound reconstruction of the argument. After this reconstruction is developed in precise detail, the authors show that the conclusion, a reading of the claim “God exists”, does not quite achieve the end Anselm desired.

The author shows that, after some considerations about the nature of speech, we can take two substantially different paths. Wittgenstein’s early philosophy is the paradigm of the first path, his later the paradigm of the second. According the author, the difference between these two conceptions is that in the late Wittgenstein, as opposed to his early conception, rejects the search for, and the clarification of, the essence of our language.

The modern (Russellian) theory of definition conceives definitions as abbreviations, so that the question of adequateness (let alone of truth-value) of definitions becomes meaningless. In this paper we show that beside Russellian conception of definitions understood as abbreviations, there is an Aristotelian conception, which exploits the notion of essence and that this conception can be rehabilitated from the standpoint of the modern logic (in particular by means of Pavel Tichý’s Transparent Intensional Logic). Also Carnap’s ‘explication’ indicates that what we feel to be a definition is frequently distinct from a Russellian definition.