Howard Robinson

I consider what I hope are increasingly sophisticated versions of ontological argument, beginning from simple definitional forms, through three versions to be found in Anselm, with their recent interpretations by Malcolm, Plantinga, Klima and Lowe. I try to show why none of these work by investigating both the different senses of necessary existence and the conditions under which logically necessary existence can be brought to bear. Although none of these arguments work, I think that they lead to interesting reflections on the nature of definition, on the conditions for possessing the property of necessary existence and point towards a different, neo-Platonic ground for God’s meeting the criteria for being logically necessary.

Nicholas Nathan tries to resist the current version of the causal argument for sense-data in two ways. First he suggests that, on what he considers to be the correct reconstruction of the argument, it equivocates on the sense of proximate cause. Second, he defends a form of disjunctivism, by claiming that there might be an extra mechanism involved in producing veridical hallucination that is not present in perception. I argue that Nathan’s reconstruction of the argument is not the appropriate one, and that, properly interpreted, the argument does not equivocate on proximate cause. Furthermore, I claim that his postulation of a modified mechanism for hallucinations is implausibly ad hoc

Thought experiments are usually employed by philosophers as a tool in conceptual analysis. We pose ourselves questions such as “Would it be the same F if p?” or “Would it count as knowledge if q,” where p and q state some bizarre circumstances that are unlikely actually to occur and may even be beyond current technical possibility. The answers we are inclined to give to such questions are held to throw light on the nature of our concepts of, in these cases, identity and knowledge. But the facts about our concepts that are unearthed in this way are implicitly assumed to be deep, not superficial, facts. They are not meant to be facts contingent upon our current linguistic usage, psychology, or social structure, where these could easily be otherwise. If they were just facts of this superficial kind, it would hardly be worth the effort of uncovering them, for they would bind no-one who preferred a different convention or practice. The conceptual truths revealed are meant to be unavoidable, in some sense, and not merely conventional: there is something Platonic or Kantian in the background. The argument of Sections 2–8 of this essay is that, in the case of the thought experiments used to throw light on our concepts of person and personal identity, the results do not seem to be deep or hard to revise, and that this is so largely because of the ontological assumptions shared by more or less all participants in the debate. I shall be arguing that it is primarily these ontological assumptions, rather than the insight into our concepts that the thought experiments are supposed to bring, that determine the answers to the questions about persons and their identity. In the final two sections I shall make some cautious qualifications to this conclusion.