Thomasson, Amie, and . Ontology Made Easy

2015, OUP USA (2015)

Abstract: Existence questions have been topics for heated debates in metaphysics, but this book argues that they can often be answered easily, by trivial inferences from uncontroversial premises. This ‘easy’ approach to ontology leads to realism about disputed entities, and to the view that metaphysical disputes about existence questions are misguided.

Comment: An interesting presentation of a way to avoid ontological disputes. Would work well as a conclusion to a course or section on ontology, to show students there might be a way to simply avoid these debates if desired.

Thomasson, Amie, and . Answerable and Unanswerable Questions

2009, In MetaMetaphysics, eds. David Chalmers, Ryan Wasserman, and David Manley. Oxford: Oxford University Press. 444-471.

Summary: Thomasson argues that merely verbal disputes arise in metaphysics when ontologists misuse the words ‘thing’ and ‘object’. Application conditions fix the conditions under which a claim can be applied or refused, but some ontological disputes involve using the terms ‘thing’ and ‘object’ in such a way that they lack application conditions. When this happens there is no way to determine the truth values of the claims being made.

Comment: This would be useful in a course on metaphysics, ontology or metametaphysics. It gives an interesting and plausible articulation of the idea that some metaphysical disputes are illegitimate in some sense (an intution that some students share). This isn't an easy paper, but it is clearly written and suitable for advanced undergraduates or graduates.

Yagisawa, Takashi, and . A New Argument Against the Existence Requirement

2005, Analysis 65 (285): 39-42.

Abstract: It may appear that in order to be any way at all, a thing must exist. A possible – worlds version of this claim goes as follows: (E) For every x, for every possible world w, Fx at w only if x exists at w. Here and later in (R), the letter ‘F’ is used as a schematic letter to be replaced with a one – place predicate. There are two arguments against (E). The first is by analogy. Socrates is widely admired now but he does not exist now. So, it is not the case that for every x, for every time t, Fx at t only if x exists at t. Possible worlds are analogous to times. Therefore, (E) is false (cf., Kaplan 1973: 503 – 05 and Salmon 1981: 36 – 40). For the second argument, replace ‘F’ with ‘does not exist’. (E) then says that for every x, for every possible world w, x does not exist at w only if x exists at w. This is obviously false. Therefore (E) is false (cf., Kaplan 1977: 498). Despite their considerable appeal, these arguments are not unassailable. The first argument suffers from the weakness inherent in any argument from analogy; the analogy it rests on may not.

Comment: A very concise argument against the claim that existence is a prerequisite for having properties. This is a familiar claim, and this paper would be useful when it comes up to show that there is controversy about it. It does presuppose a basic understanding of possible world semantics, so should be reserved for courses where students already have a grasp of such semantics or the instructor wants to teach it beforehand.