McKenzie Argument from Consciousness

My past attempt at this question was removed, but in my philosophy class we were talking about Alyce McKenzie's argument from consciousness. At the end of class we talked about how McKenzie's argument, in a materialistic view, commits the Fallacy of Division, which is where one assumes that what is true for the whole is true for all individual parts. Does anyone know why this is so? I understand Mckenzies argument and what the Fallacy of Division is but not how it commits it.