Presentists, who believe that only present objects exist, should accept a thisness ontology, since it can do considerable work in defence of presentism. In this paper, I propose a version of presentism that involves thisnesses of past and present entities and I argue this view solves important problems facing standard versions of presentism.

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)

The project of grounding necessity in essence often goes together with the model of essence that assimilates the constitutive essence of an object to the definition of it. The paper argues that if the grounding project is to succeed, the definitional model must be questioned. Like any object whatever, a concrete individual is necessarily identical to that individual. It is argued that this necessity can have an essential ground only if the primitive identity property of it or its thisness (...) is essential to it, and the thisness is in its constitutive essence while not in the definition of it. A concrete individual is in essence partly definable but not fully explainable, for the definition of it forms a crucial part of its constitutive essence, but the constitutive essence includes something fundamental beyond definition or explanation. The definitional model must give way to a model of essence that accommodates this. (shrink)

A tongue-in-cheek send-up of certain aspects of existentialism written by a well-known logician and philosopher who had a serious affair with existentialism in his youth. It was never submitted for publication and is finally being made available here posthumously with the permission of Helen Eberle. To the best of my recollection it was written some time in the mid/late 1980s. -- Gary H. Merrill.

This paper evaluates six contenders which might be invoked by essentialists in order to meet Quine’s challenge, viz., to provide necessary and sufficient conditions for the crossworld identity of individuals: (i) an object’s qualitative character; (ii) matter; (iii) origins; (iv) haecceities or primitive non-qualitative thisness properties; (v) “world-indexed properties”; and (iv) individual forms. The first three candidates, I argue, fail to provide conditions that are both necessary and sufficient for the crossworld identity of individuals; the fourth and fifth criteria (...) are open to the charge that they do not succeed in meeting Quine’s demand in an explanatorily adequate fashion. On balance, then, individual forms, or so I propose, deserve to be taken very seriously as a possible response to Quine’s challenge, especially by neo-Aristotelians who are already committed to a hylomorphic conception of composite concrete particular objects for other reasons. Theorists who also accept a non-modal conception of essence, i.e., a conception according to which essence is not reducible to modality, in addition face the further difficult task, over and above what is required to meet Quine’s challenge, of having to explain how an object’s de re modal profile in some way follows from facts about its essence. Haecceities and world-indexed properties, as I indicate, are unlikely to be of much help with respect to this second challenge, while the forms of hylomorphic compounds are in fact well-suited for this purpose. (shrink)

The way in which vision represents objects as being the same despite movement and qualitative changes has been extensively investigated in contemporary psychology. However, the formal properties of the visual sameness relation are still unclear, for example, whether it is an identity-like, equivalence relation. The paper concerns one aspect of this problem: the transitivity of visual sameness. Results obtained by using different experimental paradigms are analysed, in particular studies using streaming/bouncing stimuli, multiple object tracking experiments and investigations concerning object-specific preview (...) benefit, and it is argued that the transitive interpretation of visual sameness is the most plausible given the current stage of knowledge. What is more, it is claimed that the way in which visual sameness is represented suggests that in some cases it should be characterized as a “primitive sameness”, similarly as in philosophical theories postulating “thisness”. (shrink)

After sketching some aspects of truthmaker doctrines and "truthmaker projects", and canvassing some prima facie objections to the latter, I turn to an issue which might seem to involve confusion about the nature of character of truthmakers if such there be, viz for statements of identity and (specially) distinctness. The real issue here is versions of the Identity of Indiscernibles. I discuss ways of discriminating versions, which are almost certainly true but trivial, which almost certainly substantive but false, and explore (...) an interesting intermediate possibility which might if developed yield a plausibly true yet not-entirely-trivial version of the doctrine: it is equivalent to what I call "the Denial of Bare Distinctness". (shrink)

Lynne Baker’s case for the incompatibility of naturalism with the first-person perspective raises a range of questions about the relationship between naturalism and the various properties involved in first-person perspectives. After arguing that non-qualitative properties—most notably, haecceities like being Lynne Baker—are ineliminably tied to first-person perspectives, this paper considers whether naturalism and non-qualitative properties are, in fact, compatible. In doing so, the discussion focus on Shamik Dasupgta’s argument against individuals and, in turn, non-qualitative properties. Several strategies for undermining Dasgupta's argument (...) are considered, drawing on de re laws and haecceitistic possibilities. Finally, an analogy is drawn between naturalism and platonism regarding mathematical entities and naturalism's parallel commitment to individuals. I conclude that naturalists are obliged to posit non-qualitative properties. (shrink)