The essays in this topical collection provide a thorough discussion of that question. Drawn mostly from contemporary philosophy, the collection nevertheless begins a bit further back: with Gottlob Frege's "Function and Concept," two contributions from Bertrand Russell, and F.P. Ramsey's "Universals."

More recent selections are included from W.V.O. Quine ("On What There Is"), Frank Jackson, Michael Devitt, D.M. Armstrong, Donald C. Williams, Keith Campbell, Chris Daly, David Lewis, Sydney Shoemaker, and co-editor D.H. Mellor.

The volume will be of special interest to readers looking for sources on the problem of universals. Naturally each contribution deals with the problem to some extent, but particularly interesting is an exchange between Michael Devitt and D.M. Armstrong. Nominalists and realists sometimes talk past each other about this problem, and sure enough, much of the exchange between Devitt and Armstrong has to do with (a) why nominalists don't think there really _is_ a "problem" of universals and (b) why realists think nominalists are being all but willfully blind.

In a spirited but cheerfully sporting verbal tennis match, Devitt responds to Armstrong's complaints (in _Universals and Scientific Realism_) about "ostrich nominalism" by attacking "mirage realism" instead. Armstrong offers a rejoinder which he thinks improves on his earlier discussion. The two part friends, with no injuries.

There is also good discussion on trope theory and "abstract particulares," as one might expect from the inclusion of essays by Williams, Campbell, and Daly. This is an excellent collection both overall and in detail.

It will be of interest to readers of D.M. Armstrong's _Universals: An Opinionated Introduction_, and it will also fit well alongside Andrew Schoedinger's topical collection _The Problem of Universals_. (There is surprisingly little overlap between Schoedinger's volume and the present one. Ramsey's "Universals," Russell's "The World of Universals," and Quine's "On What There Is" are the only essays common to the two collections.)

Mellor says much in a short space, and he says it in an entertaining (though not always easy to understand) way. The first half of this book defends a token-reflexive analysis of tensed discourse against A-theoretical objections. The second half gives arguments in favor of Mellor's untensed theory of time. Mellor's theory is distinguished from other versions of the B-theory in that it 1) treats change as the possession of incompatible non-relational properties by a single thing at different times, 2) defines temporal order as the direction of causation, and 3) denies that people and objects (as opposed to events) have temporal parts. This makes for a very interesting picture of the world.

As interesting as the book was, I wish Mellor had spent more time in the second half trying to respond to possible objections. For example, he is committed to the view that a single object can exist fully at two distinct temporal locations and possess incompatible properties at each location. Though he discusses McTaggart at length, he does not seem to notice that this part of his theory might be open to McTaggart-like objections.

This is a good piece of philosophy. It should interest anyone working in the philosophy of time, though one might want to look elsewhere for more sustained arguments. The book's most important contribution is probably its defense of B-theoretical semantics. If nothing else, it is a source of fascinating and original ideas.

D.H.Mellor is one of the most important figures in contemporary methaphysics. Real Time II is a not just a revision, but a complete reworking of his tenseless theory of time, as developed in Real Time (1981). The book deals with the basic metaphysical question: what is time? Influenced by McTaggart's proof, Mellor raises his arguments against an a-theory of time, and in developing his own b-theory, he takes us through the main concerns about time e.g. the presence of experience, time and space, change, causation and the linearity of time. Taking us one more step away from the classical considerations of a past, present and future, the book gives the reader an essential ground for the contemporary philosophy of time.