Online research in philosophy

The metaphysical relation of supervenience has seen most of its service in the fields of the philosophy of mind and ethics. Although not repaying all of the hopes some initially invested in it – the mind-body problem remains stubbornly unsolved, ethics not satisfactorily naturalized – the use of the notion of supervenience has certainly clarified the nature and the commitments of so- called non-reductive materialism, especially with regard to the questions of whether explanations of supervenience relations are required and whether such explanations must amount to a kind of reduction.

This is one of two papers about emergence, reduction and supervenience. It expounds these notions and analyses the general relations between them. The companion paper analyses the situation in physics, especially limiting relations between physical theories. I shall take emergence as behaviour that is novel and robust relative to some comparison class. I shall take reduction as deduction using appropriate auxiliary definitions. And I shall take supervenience as a weakening of reduction, viz. to allow infinitely long definitions. The overall claim of this paper will be that emergence is logically independent both of reduction and of supervenience. In particular, one can have emergence with reduction, as well as without it; and emergence without supervenience, as well as with it. Of the subsidiary claims, the four main ones (each shared with some other authors) are: (i): I defend the traditional Nagelian conception of reduction (Section 3}); (ii): I deny that the multiple realizability argument causes trouble for reductions, or ``reductionism'' (Section 4); (iii): I stress the collapse of supervenience into deduction via Beth's theorem (Section 5.1); (iv): I adapt some examples already in the literature to show supervenience without emergence and vice versa (Section 5.2).