Abstract
What is the connection between modelling thought and modelling the brain? In a model
(as understood here), we strip away from the modelled system some non-essential features
and retain some essential ones. What are the essential features of thought that are to be re-
tained in the model, and conversely, what are its inessential features, that may be stripped
away in the model? According to a prevalent view in contemporary science and philoso-
phy, thought is a computation, and therefore its essential features are its computational
features. A necessary part of the computational view of thought is the idea that the same
computation can be realised by, or implemented in, physically heterogeneous systems, an
idea known as “Multiple Realizability” of the computational features or properties by the
physical ones. I will describe why the very idea of Multiple Realizability, especially in the
case of mental computation, entails mind-body dualism, and explore some implications
of this conclusion concerning the question of which are the essential features of thought
to be retained in modeling it.