I have started studying philosophy of mind and I am currently reading an introduction to the field. The first topic that is presented in the book is dualism of the Cartesian brand, and the case for it is made, roughly, thus:
- Material objects are characterized by such things as extension, shape, definite location in space and being made of elementary particles which could be described by a physical theory
- Mental objects, such as sensations, perceptions and thoughts, exist
- Sensations, perceptions and thoughts are not extended, have no shape nor definite locations in space, and are not made up of particles
- Therefore, sensations, perceptions and thoughts are not material.
Honestly, it seems a good argument to me. If I think about a desire I am feeling, for istance, I could argue that it is my body, and so it would have a location in space, but it would not make sense to me to say that this desire has a shape, or that its position could be exactly pinpointed, or that it could be observed or detected through technological devices (even potentially!).
This notwithstanding, objections to the argument are not considered in the rest of the book. The only thing it has to say about dualism is that it demands an explanation of how the immaterial and the material interact causally. A lot more space is devoted to potential refutations of the knowledge argument, the zombie argument and the likes.
Even perusing some literature on the topic, the closest thing I have found to a discussion of this argument is in Smart's paper Sensations and Brain Processes. The author seems to argue, at least as far as I can grasp, that premise 2 is false: there is no such thing as a perception or a sensation or a thought, but only experiences of having a perception, or a sensation or a thought.
Besides this, I could not find references to the argument even in anti-materialist treatments (except for the book I'm studying, of course).
Why is this argument overlooked? Is it that bad?