Markku Keinänen

The goal of formal ontological inquiry is to reveal the categorial structure of the mind-independent reality. In the first part of this article, I criticize two popular ways to study the categorial structure, Strong and Weak Modelling. In the second part of the article, I present my positive account. The systematic description of the different kinds of entities assumed by our commonsense conceptions forms a starting-point of the study of the categorial structure of the world. However, it is the task of Revisionary Metaphysics to seek for the best conception of the categorial structure. Revisionary Metaphysics proceeds as testing alternative conceptions of the categorial structure. The main new contribution of the article is to propose certain general principles for the comparison of such alternative conceptions.

We argue that if one wishes to be a realist, one should adopt a Neo-Aristotelian ontology involving tropes instead of a Russellian ontology of property universals and objects. Either Russellian realists should adopt the relata-specific relational tropes of instantiation instead of facts, or convert to Neo-Aristotelian realism with monadic tropes. Regarding Neo-Aristotelian realism, we have two novel points why it fares better than Russellian realism. Instantiation of property universals by tropes and characterization or inherence between tropes and objects are more transparent ontological notions than relational inherence, which is assumed in Russellian realism with the relational tropes of instantiation. Neo-Aristotelian realism makes better sense about abstract universals, which are a more viable option than concrete universals.

This paper is the first trope-theoretical reply to E. J. Lowe’s serious dilemma against trope nominalism in print. The first horn of this dilemma is that if tropes are identity dependent on substances, a vicious circularity threatens trope theories because they must admit that substances are identity dependent on their constituent tropes. According to the second horn, if the trope theorist claims that tropes are identity independent, she faces two insurmountable difficulties. (1) It is hard to understand the ontological dependence of tropes on substances. (2) The identity-conditions of tropes cannot be determinate, which threatens the determination of the identity-conditions of substances. Our reply to the first horn of Lowe’s dilemma is to deny the identity dependence of tropes. Yet we can avoid the second horn because our theory can explain the ontological dependence of tropes on substances and the fully-determined identity-conditions of both tropes and substances.