Nikk Effingham

I have previously argued in a paper with Robson that a particular time travel scenario favours perdurantism over endurantism on the grounds that endurantists must give up on the Weak Supplementation Principle. Smith has responded, arguing that the reasons we provided are insufficient to warrant this conclusion. This paper agrees with that conclusion (for slightly different reasons: that even the perdurantist has to give up on the Weak Supplementation Principle) but argues that the old argument can be supplanted with a new one

The Multiverse Thesis is a proposed solution to the Grandfather Paradox. It is popular and well promulgated, found in fiction, philosophy and (most importantly) physics. I first offer a short explanation on behalf of its advocates as to why it qualifies as a theory of time travel (as opposed to mere 'universe hopping'). Then I argue that the thesis nevertheless has an unwelcome consequence: that extended objects cannot travel in time. Whilst this does not demonstrate that the Multiverse Thesis is false, the consequence should give pause for concern. Even if it does not lead one to reject the thesis, I briefly detail some reasons to think it is interesting nonetheless

It is a common view that if composition as identity is true, then so is mereological universalism (the thesis that all objects have a mereological fusion). Various arguments have been advanced in favour of this: (i) there has been a recent argument by Merricks, (ii) some claim that Universalism is entailed by the ontological innocence of the identity relation, (or that ontological innocence undermines objections to universalism) and (iii) it is entailed by the law of selfidentity. After a preliminary introduction to the competing theories of persistence (necessary for a discussion of Merricks’ argument) I examine each in turn and demonstrate how they fail. I conclude that the prejudice that if composition as identity is true then Universalism is true, is unwarranted. Thus one motivation for believing Universalism is lost and those who believe composition as identity should now be receptive to some form of restricted composition.

In this engaging and wide-ranging new book, Nikk Effingham provides an introduction to contemporary ontology - the study of what exists - and its importance for philosophy today. He covers the key topics in the field, from the ontology of holes, numbers and possible worlds, to space, time and the ontology of material objects - for instance, whether there are composite objects such as tables, chairs or even you and me. While starting from the basics, every chapter is up-to-date with the most recent developments in the field, introducing both longstanding theories and cutting-edge advances. As well as discussing the latest issues in ontology, Effingham also helpfully deals in-depth with different methodological principles and introduces them alongside an example ontological theory that puts them into practice. This accessible and comprehensive introduction will be essential reading for upper-level undergraduate and post-graduate students, as well as any reader interested in the present state of the subject