We investigate the connection between interference and computational power within the operationally defined framework of generalised probabilistic theories. To compare the computational abilities of different theories within this framework we show that any theory satisfying four natural physical principles possess a well-defined oracle model. Indeed, we prove a subroutine theorem for oracles in such theories which is a necessary condition for the oracle model to be well-defined. The four principles are: causality, purification, strong symmetry, and informationally consistent composition. Sorkin has (...) defined a hierarchy of conceivable interference behaviours, where the order in the hierarchy corresponds to the number of paths that have an irreducible interaction in a multi-slit experiment. Given our oracle model, we show that if a classical computer requires at least n queries to solve a learning problem, because fewer queries provide no information about the solution, then the corresponding “no-information” lower bound in theories lying at the kth level of Sorkin’s hierarchy is \. This lower bound leaves open the possibility that quantum oracles are less powerful than general probabilistic oracles, although it is not known whether the lower bound is achievable in general. Hence searches for higher-order interference are not only foundationally motivated, but constitute a search for a computational resource that might have power beyond that offered by quantum computation. (shrink)

Contemporary foundationalists prefer Moderate Foundationalism over Strong Foundationalism. In this paper, we assess two arguments against the former which have been recently defended by Timothy McGrew. Three theses are central to the discussion: that only beliefs can be probabilifying evidence, that justification is internal, in McGrew’s sense of the term, and that only beliefs can be nonarbitrary justifying reasons.

This paper approaches the ‘Drexler-Smalley’ debate on nanotechnology from a neglected angle – the common denominator of ‘the frontier’ as a metaphor for scientific exploration. For Bensaude-Vincent, the debate exemplifies the clash of ‘two cultures’ – the ‘artificialist’ and biomimetic’ schools. For us, the portrayal of nanosphere as ‘new frontier’ stymies the prospect of genuine inter-cultural debate on the direction of molecular engineering. Drawing on Brandon, the‘dominium’ impulse of European imperialism is contrasted to the ‘communitas’ tradition of Native America. Proposing (...) a single label – hybridist – for both schools, we juxtapose to this approach the holistic disposition of indigenous North American science. (shrink)