In Chapter I, we contrasted two conceptions of what it is to be a person. On the one hand, there is the two-component picture, the view that a person consists of a physical body and an immaterial Cartesian Mind. On the other hand, there is the naturalistic view which maintains that a person is an organism without any immaterial components or additions, and which regards the mind as being (in some sense which needs to be further explained) grounded in the structural complexity of our brains. Since the first, dualist, position has been shown to run into very serious problems, let's now consider the alternative. In the present chapter we will outline a naturalistic framework for understanding what it is to be a person, with a view to developing the framework in subsequent chapters. As we shall see, the basic approach is hardly new: indeed it can be traced back to Aristotle. Later, we will examine part of Aristotle's own discussion: but before doing that, it will be helpful to explore his kind of anti-dualist approach more informally.

Let's start by stepping back from the question about what it is to have a mind to a simpler question: what is the difference between animate and inanimate objects – what distinguishes amoeba, plants and animals from stones, lumps of iron and dead pieces of wood? To focus on a specific case, what is the difference between a living seed of corn and a lifeless pebble? To casual inspection, both look to be just hard little lumps of stuff: but there are of course crucial differences in their potentialities.