Mark Heller

This provocative book attempts to resolve traditional problems of identity over time. It seeks to answer such questions as 'How is it that an object can survive change?' and 'How much change can an object undergo without being destroyed'? To answer these questions Professor Heller presents a theory about the nature of physical objects and about the relationship between our language and the physical world. According to his theory, the only actually existing physical entities are what the author calls 'hunks', four-dimensional objects extending across time and space. This is a major contribution to ontological debate and will be essential reading for all philosophers concerned with metaphysics.

René Descartes, one of the dominant figures in the history of philosophy, has been accused of one of the most obvious mistakes in the history of philosophy — the so-called cartesian circle. It is my goal in this paper to arrive at an understanding of Descartes's work that attributes to him a theory that should be of philosophical interest to contemporary epistemologists, is consistent with, and suggested by, the actual text, and avoids the circle.I begin with a brief explanation of the supposed circle. In his search for absolute certainty Descartes requires that in order for a proposition to be an instance of knowledge it must be indubitable for the knower, and in order for it to be indubitable for the knower she must be able to eliminate any possibility of the belief's being false. It is to provide a means to satisfy this requirement that Descartes proposes the principle whatever is clearly and distinctly perceived cannot be false.And it seems that Descartes's defense of CD traps him in the circle.

In 1962 Hilary Putnam forced us to face the possibility of robot cats. More than twenty years later Daniel Dennett found himself doing battle with mad scientists and other “bogeymen.” Though these two examples are employed in different philosophical arena, there is an important connection between them that has not been emphasized. Separating the concept associated with a kind term from the extension of that term, as Putnam and others have urged, raises the possibility of accepting counterexamples to compatibilistic analyses without rejecting compatibilism. Even if no compatibilist analysis of our concept of free action is acceptable, a compatibilist account of the essential nature of free action may be.