An Anthropologist on Mars is not a book about autism. Rather, it's a series of case studies which examine the brain's ability to reconstitute "self" or identity when it is injured or diseased. For example, one chapter examines an individual who suffered a severe brain tumor in his 20s. Another chapter examines Temple Grandin, the subject of Thinking in Pictures.
It's a fascinating read, with remarkable subjects. The common theme throughout the book is the nature of the injury or disease, and its relation to self. Of Tourette's, Sacks writes:
Any disease introduces doubleness into life - an "it," with its own needs, demands, limitations. With Tourrette's the "it" takes the form of explicit compulsion, a multitude of explicit impulsions and compulsions: one is driven to do this, to do that, against one's own will, or in deference to the alien will of the "it." There may be a conflict, a compromise, a colusion between these wills....
But the relation of disease and self, "it" and "I," can be particularly complex in Tourette's, especially if it has been present from early childhood, growin up with the self, intertwining itself in every possible way. The Tourette's and self shape themselves each to the other, come more and more to complement each other, until finally, like a long-married couple, they become a single, compound being. This relation is often destructive, but it can also be constructive, can add speed and spontaneity and a capacity for unusual and sometimes startling performance. For all its intrusiveness, Tourette's may be used creatively, too.
This concept of self echoes statements I've read from neurodiversity advocates. For example, autistic advocate Jim Sinclair states:
Autism is a way of being. It is pervasive; it colors every experience, every sensation, perception, thought, emotion, and encounter, every aspect of existence. It is not possible to separate the autism from the person.
Moreover, Sinclair rejects the designation "person with autism", preferring "autistic person". Sinclair compares describing an individual as a "person with autism" to describing a man as a "person with maleness."
As illustrated in Sacks' case studies, this concept of self is not unique to autism. In my opinion, while the "I" often fuses with the "it" in a theory of mind sense, the "I" does not negate the "it" in the biological sense. Autism - the "it" - exists independent of individual as a genetic condition. (Of course, the genetics are yet to be fully explicated.)
The analytic framework set forth above sheds light on the differences between the pro-cure and neurodiversity camps. In basic terms, neurodiversity advocates reject the separateness of the "it", while "curebies" refuse to acknowledge, or value, the impact of the "it" on identity.