One man's modus ponens is another man's modus tollens. That the 'honestly' requires other entities is proof that this cannot be an ethical system which encompasses all rational beings.
And yet humans kill eachother. His only possible retort is that some humans are not rational. Better hope that nobody builds an "irrational" AI.
...has finally been published.
Contents:
The issue consists of responses to Chalmers (2010). Future volumes will contain additional articles from Shulman & Bostrom, Igor Aleksander, Richard Brown, Ray Kurzweil, Pamela McCorduck, Chris Nunn, Arkady Plotnitsky, Jesse Prinz, Susan Schneider, Murray Shanahan, Burt Voorhees, and a response from Chalmers.
McDermott's chapter should be supplemented with this, which he says he didn't have space for in his JCS article.