Date of Award

Spring 1-1-2013

Document Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

Graeme Forbes

Second Advisor

Robert Rupert

Third Advisor

Michael Tooley

Fourth Advisor

Graham Oddie

Fifth Advisor

Allan Franklin


Abstract: You could be going for a walk right now. This seems true—but what makes it true? Here is a popular answer : It is true that you could be going for a walk right now because there exists some possible world (beyond the actual world) where you are going for a walk now; or else, because there is some abstract, representational entity which represents you as going for a walk now. I think this is mistaken. I take a more common-sense approach, arguing instead that the modal truths (i.e., truths about metaphysical possibility and necessity) are made true by the capabilities, or dispositional properties, of actual objects. For instance, in the case just stated, it is true that you could be going for a walk right now so long as you have the capacity to do so.

In light of this conclusion, I then argue for three related ones: (1) First, an essential property of each individual is its unique origin. For instance, the table in front of me, which originated from a particular hunk of pine wood, could not have originated from, say, a block of ice. (2) Second, metaphysical possibility is just a unique species of de re modality, such that the metaphysical possibilities are just the ways this world could be. (3) Finally, an essential property of the actual world is its unique origin, such that all of the metaphysical possibilities must share some initial, causally potent entity or entities in common. In short, either some causally potent necessary being exists—e.g., God—or else there is necessarily an actual infinite number of contingent beings; namely, a beginningless series of contingent causes.

Included in

Metaphysics Commons