Martin Glazier

This short book gives an overview of contemporary work on essence and explores a new approach to the ancient debate over whether the essences of things lie inside or outside our everyday world.

If philosophers someday complete their investigation into fundamental metaphysics, what will we have achieved? I argue that we will have summarized the fundamental truths and identified what is relevant to a certain kind of explanation of the nonfundamental aspects of reality.

According to orthodoxy, if something is actually true, then it is necessary that it is actually true. I argue that orthodoxy is mistaken and that things could have been actually different.

If the tiles of a mosaic are arranged symmetrically, then the image those tiles constitute must be symmetric as well. I formulate and defend the general principle at work in this case and show how it supports powerful objections to a range of reductionist views.

Can all of science be reduced to fundamental physics? And in particular, can the laws of the special sciences be reduced to the laws of fundamental physics? I examine whether the 'Mentaculus' of David Albert and Barry Loewer supports a positive answer.

Most philosophers accept the principle "if actually p, then necessarily actually p", yet doubts about this principle go back to the very beginning of the formal study of the logic of actuality. We develop the logic that results if the principle is rejected.

I develop a puzzle whose resolution requires us to recognize an unfamiliar distinction between two forms of metaphysical modality, each bearing a different relationship to time.

It's a popular view that everything about the ordinary macroscopic world can be explained in terms of microscopic objects like particles. I show that this view encounters great difficulty when subjected to even the most basic questioning.

I raise an objection to priority monism, the view that the whole cosmos is the only substance there is. The objection is that although every substance is necessarily a substance, for the priority monist the cosmos is not necessarily a substance.

Philosophers since Kripke have observed a contrast between those forms of necessity that are genuine, such as metaphysical and natural necessity, and those that are not, such as epistemic and deontic necessity. But what is it for a form of necessity to be genuine? I argue that the genuine forms of necessity are those that provide what I call 'necessitarian' explanation.

Could I have been someone other than who I am? Philosophers from Williams to Nagel to Lewis have been tempted to answer 'yes', but how can we make sense of such a view? I argue that to say that it is contingent who I am is to say that it is contingent what perspective I have, in a distinctively metaphysical sense of perspective.

I survey the philosophical literature on grounding explanation and its connection to metaphysical ground.

Sometimes a thing is the way it is because it lies in its very nature to be that way. I show that this 'essentialist' form of explanation is a form of metaphysical explanation distinct from grounding explanation. Not only is essentialist explanation ubiquitous in philosophy, I argue, it is also an ultimate form of explanation.

Many philosophers have thought that everything must admit of explanation in terms of the fundamental facts. I show how to formulate this thought precisely and argue that it requires the existence of fundamental metaphysical laws.