We do have an organ for understanding and recognizing moral facts. It is called the brain. - Paul Churchland

Your brain is far too complex and mercurial for its behavior to be predicted in any but the broadest outlines or for any but the shortest distances in the future.

The basic idea is that cognitive activities are ultimately just activities of the nervous system; and if one wants to understand the activities of the nervous system, then the best way to gain that understanding is to examine the nervous system itself.

How such an elaborate theory could have become so widely accepted – on the basis of no systematic evidence or critical experiments, and in the face of chronic failures of therapeutic intervention in all of the major classes of mental illness... – is something that sociologists of science and popular culture have yet to fully explain.