A side note.

My mother is a psychologist, father - an applied physicist, aunt 1 - a former morgue cytologist, aunt 2 - a practicing ultrasound specialist, father-in-law - a general practitioner, husband - a biochemist, my friends (c. 5) are biologists, and most of my immediate coworkers teach either chemistry or biology. (Occasionally I talk to other people, too.) I'm mentioning this to describe the scope of my experience with how they come to terms with the 'animal part' of the human being; when I started reading LW I felt immediately that people here come from different backgrounds. It felt implied that 'rationality' was a culture of either hacking humanity, or patching together the best practices accumulated in the past (or even just adopting the past), because clearly, we are held back by social constraints - if we weren't, we'd be able to fully realize our winning potential. (I'm strawmanning a bit, yes.) For a while I ignored the voice in the back of my mind that kept mumbling 'inferential distances between the dreams of these people and the underlying wetware are too great for you to estimate', or some such, but I don't want to anymore.

To put it simply, there is a marked difference within biologists in how reverently they view the gross (and fine) human anatomy, in how easily they accept that a body is just a thing, composed of matter, with charges and insulation and stuff -just a system of tubes, but still not a car in which you can individually tweak the axles and the windshield (probably). (This is why I think Peter Watts is so popular on LW - the idea that you can just tinker with circuitry and upgrade people.

Psychologists are the most 'gentle', they and the doctors have too much 'social responsibilities' baked in to comfortably discuss people as walking meat. Botanists (like me) don't have enough knowledge to do it, but we at least are aware of this. Biochemists are narrow-minded by necessity (too many pathways). Vertebrate zoologists are best (Steinbeck, I think, described it in his book about the Sea of Cortes), in that you can count on them to be brutally consistent. Physicists - at least the one I know - like to talk about 'open systems' and such, but they (he) could just as plausibly speak about some totally contrived aliens.

I know it is dishonest to ask LW-ers to spend time on studying exactly human anatomy, but even a thorough look at some skeleton should give you a vibe of how defined human bodies are. There are ridges on the bones. There are seams. Try to draw them, to internalize the feeling.

I'm sorry for the cavalier assuming of ignorance, but I think at least some of you can benefit from my words.