The paper is a survey of contemporary quidditism, understood as two interrelated metaphysicalpositions — recombinatorial quidditism, which is an account of the nature of possibilities, andindividuation quidditism, which is concerned with the problem of how to individuate properties.I have three aims: to examine the commitments and consequences of both views, to investigatethe relationships between them, and to sketch the logic of the dispute between structuralism andquidditism. I explain how these views relate to Ramseyan humility, according to which we cannotknow the (...) fundamental structure of the world. (shrink)

According to strong pluralism, objects distinct by virtue of their modal properties can coincide. The most common objection towards such view invokes the so-called Grounding Problem according to which the strong pluralist needs to explain what the grounds are for supposed modal differences between the coincidents. As recognized in the literature, the failure to provide an answer to the Grounding Problem critically undermines the plausibility of strong pluralism. Moreover, there are strong reasons to believe that strong pluralists cannot provide an (...) explanation of the Grounding Problem. In this paper, we argue that strong pluralism can be motivated independently of the successful answer to the Grounding Problem. In order to achieve that aim, we provide a haecceitistic interpretation of strong pluralism according to which strong pluralism should be read as a position committed to the existence of primitive individuals, i.e., the individuals that have their criteria of individuation independently of their qualitative profiles. That said, we do not aim at defending haecceitism. Instead, our aim is rather modest: we want to provide a new way for the strong pluralist to supplement his view to make it more watertight. (shrink)

According to the traditional view, visual objects can be characterized as bundles of features and locations. This initially plausible idea is contested within the contemporary psychology and philosophy of perception, where it is claimed that the visual system can represent objects as merely ‘this’ or ‘that’, in abstraction from their qualities. In this paper, I consider whether philosophical and psychological arguments connected with the rejection of the ‘bundle’ view of visual objects show that it is needed to postulate an additional, (...) purely individualizing characteristic, known in the philosophical tradition as ‘thisness’, within the structure of visual objects. I argue that the phenomenon of asymmetry of errors observed in Multiple Object Tracking experiments strongly suggests that reference to ‘thisness’ is needed if we are to formulate a proper diachronic identity criterion of visual objects. (shrink)

Two arguments are offered here for postulating individual essences of concrete individuals on top of their sortal essences. One is the explanatory gap argument, the other draws on the analogy with the individual essences of events presupposed in single causal explanations. These arguments support qualitative individual essences with explanatory goals as opposed to hybrid impure relational essences accounting for origin and numerical identity. It is highlighted why origin properties as parts of impure relational essences do not yield genuine de re (...) constructions. The distinction between the two types of individual essences is traced back to the ambiguity of the very notion of individuation. (shrink)

In some sense, both ontological and epistemological problems related to individuation have been the focal issues in the philosophy of mathematics ever since Frege. However, such an interest becomes manifest in the rise of structuralism as one of the most promising positions in recent philosophy of mathematics. The most recent controversy between Keränen and Shapiro seems to be the culmination of this phenomenon. Rather than taking sides, in this paper, I propose to critically examine some common assumptions shared by both (...) parties. In particular, I shall focus on their assumptions on haecceity as an individual essence, haecceity as a property, the classification of properties, and thereby the search for the principle of individuation in terms of properties. I shall argue that all these assumptions are mistaken and ungrounded from Scotus’ point of view. Further, I will fathom what consequences would follow, if we reject each of these assumptions. (shrink)

While it is widely accepted that human vision represents objects, it is less clear which of the various philosophical notions of ‘object’ adequately characterizes visual objects. In this paper, I show that within contemporary cognitive psychology visual objects are characterized in two distinct, incompatible ways. On the one hand, models of visual organization describe visual objects in terms of combinations of features, in accordance with the philosophical bundle theories of objects. However, models of visual persistence apply a notion of visual (...) objects that is more similar to that endorsed in philosophical substratum theories. Here I discuss arguments that might show either that only one of the above notions of visual objects is adequate in the context of human vision, or that the category of visual objects is not uniform and contains entities properly characterized by different philosophical conceptions. (shrink)