Identity and properties in metaphysics of science 3800-IPMS23-S

This seminar will focus on the fundamental metaphysical questions regarding the concept of individual objects, their identity and discernibility, their properties and relations, as well as their modal profiles. According to a popular ontological and semantical view, all facts taking place in the world can be reduced to ‘individualized’ or ‘atomic’ facts expressible in the form of (a combination of) elementary sentences attributing properties and relations to individual objects. Thus the underlying assumption is that there are two categories of objects: bare, property-less entities (individuals), and properties with relations. However, the first category of objects raises a number of epistemological and ontological concerns. There are many philosophers who reject the above-mentioned view and adopt instead a broad position of generalism, which prohibits the use of individual constants referring to bare particulars. The only admissible linguistic expressions are: predicates denoting genuine properties and relations, variables with quantifiers, and possibly the symbol of identity (even though this is controversial and requires a separate discussion). Moreover, given that bare individuals do not differ from each other with respect to any properties, the generalists often assume that an appropriate language should be permutation-invariant. A radical version of generalism, defended by Shamik Dasgupta, jettisons individuals altogether, assuming only the existence of properties and relations This of course requires a new linguistic and formal representation of ordinary statements of fact, which will be discussed in the seminar.

A related problem is how to precisely characterize the concept of genuine properties and relations, in order to avoid including so-called impure properties, such as being the first-born son of Napoleon. Including such properties in a generalist, non-individualistic language defeats the purpose, since in order to interpret appropriate predicates, we have to make reference to certain individuals regardless of their possessed qualities (keep in mind that the property of being the first-born son of Napoleon is not the same as the property of being the first-born son of a person possessing such-and-such DNA). Yet philosophers disagree how we should define qualitative, or pure properties, and some even claim that this can’t be done. We will discuss some main attempts to make precise a distinction between pure and impure properties, and we will analyze their shortcomings and possible ways to repair them.

Another connected issue is the modal status of individuals. There are two dominating views regarding modality de re (modality of statements about individuals): haecceitism and anti-haecceitism. Haecceitism claims that it is possible to have two qualitatively indistinguishable situations which nevertheless differ with respect to which individuals occupy which positions (such a difference is commonly called “haecceitistic”). Anti-haecceitism denies the existence of such a possibility. The debate between these two approaches (with the third one being David Lewis’s ‘cheap haecceitism’) rages on with no end in sight. Recently, a number of arguments in favor of the stance of haecceitism have been proposed, making reference to the probability calculus, counterfactual conditionals, as well as to some hypothetical scenarios involving classical physical systems. On the other hand, anti-hacceitism seems to receive strong support from science, in particular physics. Anti-haecceitist versions of modality de re based on the concept of essential properties (or, more broadly, essential relational structures) fit well the way quantum mechanics describes states of systems of many particles. Essentialist interpretations of spacetime regions and points also help solve the well-known puzzle affecting general relativity, namely the hole argument. Thus while discussing these pure metaphysical and semantical issues we will enter the area of philosophy of physics in its latest form.