The major debate in the philosophy of time, being, and becoming is between defenders of the tenseless theory of time and defenders of the tensed theory of time. During the late twentieth century into the early twenty-first century, the tenseless theory of time was defended by such philosophers as D.H. Mellor, Graham Nerlich, and L. Nathan Oaklander. The tenseless theory implies that temporal features of events consist only of relations of simultaneity, earlier, and later than, and that all events are ontologically equal, regardless of when they occur. The tensed theory, which has many versions, is advocated by such philosophers as William Lane Craig, Quentin Smith, and Michael Tooley. The tensed theory of time implies that some or all of the words past, present, and future are needed to describe time, although what is understood by the words future, present, and...