Human is an animal.  It is an Ape from the beginning.<p>And the first thing that the monkey that actually got its head transplanted on another monkey body was to bite a nearby surgeon, before to fall unconscious and die.  So I guess it was painful.<p>It was not a head exchange, and the monkey that loss its body was not saved.<p>Would it be ethical to you if 100 Houyhnhnms[1] got cured from paralysis if hundred human lost their head?<p>Of course, I&#x27;m not aware of any Houyhnhnm existing, so this can not be applied.<p>[1]: <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Houyhnhnm" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Houyhnhnm</a>