Physicists Brian Greene and Max Tegmark both make variants of the claim that if the universe is infinite and matter is roughly uniformly distributed, then there are infinitely many “people with the same appearance, name and memories as you, who play out every possible permutation of your life choices.” In this paper I argue that--while our current best theories in astrophysics may allow one to conclude that we have infinitely many duplicates whose lives are identical to our own from start (...) to finish--without either further advances in physics or advances in fields like biology, psychology, neuroscience, and philosophy, Greene’s and Tegmark’s claims about the ways in which our duplicates lives will differ from our own are not a consequence of our best current scientific theories. Rather, I argue that Greene and Tegmark’s conclusions rely on philosophically imprecise usages of the language of “possibility.”. (shrink)

It is widely believed that the semantic contents of some linguistic and mental representations are determined by factors independent of a person’s bodily makeup. Arguments derived from Hilary Putnam’s seminal Twin Earth thought experiment have been especially influential in establishing that belief. I claim that there is a neglected version of the mind-body relation which undermines those arguments and also excludes the possibility of zombies. It has been neglected because it is counterintuitive but I show that it can nonetheless be (...) intelligibly worked out in detail and all obvious objections met. This suggests that we may be faced with a choice between embracing a counterintuitive interpretation of the mind-body relation or accepting that a currently very promising theory in cognitive science, Prediction Error Minimization, faces a fundamental problem. Furthermore, blocking that threat entails that any physicalist/materialst theory of mind is freed from the spectre of zombie worlds. The proposal also makes the ideas of personal teleportation of mind uploading more plausible. (shrink)

Porpora offers an a priori argument for the conclusion that there are infinitely many thoughts that it is physically possible for us to think. That there should be such an a priori argument is astonishing enough. That the argument should be simple enough to teach to a first-year undergraduate class in about 20 min, as Porpora’s is, is more astonishing still. Porpora’s main target is Max Tegmark’s recent argument for the claim that if current physics is right, then there are (...) mental duplicates of us in far flung regions of the Universe. His argument is directed against Tegmark’s assumption that mental facts supervene upon physical facts. So, if Porpora’s argument is sound then not only is Tegmark’s argument unsound, but physicalism is also false. So, Porpora’s argument is powerful indeed. Who would have thought that a simple a priori argument, together with the physical facts, could solve the issue of whether physicalism is true?. Not I. In this paper I take a closer look at Porpora’s argument and show that it is fallacious. I also consider the other reasons Porpora gives for thinking there are infinitely many thinkable thoughts and find them similarly lacking. (shrink)

ABSTRACT In this wide-ranging interview Professor Douglas V. Porpora discusses a number of issues. First, how he became a Critical Realist through his early work on the concept of structure. Second, drawing on his Reconstructing Sociology, his take on the current state of American sociology. This leads to discussion of the broader range of his work as part of Margaret Archer’s various Centre for Social Ontology projects, and on moral-macro reasoning and the concept of truth in political discourse.