In his book Sense and Goodness without God, Richard Carrier writes:
Many animals have unique personalities, memories, and mental abilities, and can be “conscious” of their surroundings, even to a certain extent themselves. But to be able to fully perceive themselves—as a mind, as a person—requires a special organ capable of such a computation, and an organ capable of perceiving a whole pattern of such a size and complexity would have to be vastly complex itself, far more than any other sensory organ like, say, the human eye.
It just so happens that we have one of these: a cerebral cortex, the most complex biological organ in the world—in fact, as far as we know, the most complex thing in the whole universe. Animal brains are simpler, lacking this organ.
First of all, the cerebral cortex is not an organ. The brain is the organ composed of different parts, the cerebrum being one. And it is the superficial, or outer, layer of the cerebrum that is the cerebral cortex. The cerebral cortex is no more of an organ than the outer layer of the kidney – the renal cortex – is an organ.
Second, the cerebral cortex is found in all mammals, from mice to dolphins. It is simply untrue that only humans have a cerebral cortex.
Now, these are not trivial mistakes. For Carrier to proclaim that the cerebral cortex is an “organ” that animal brains “lack” tells me he is profoundly ignorant about very basic level neuroanatomy. Yet he speaks about it and he speaks with great confidence. In fact, one has to wonder how Carrier could publish such erroneous claims when 5 minutes on Google would have corrected him. It would seem he was so confident in his ignorant views that he couldn’t be bothered to fact check them.