Excellent essay, though I am a little surprised you did not reference two philosophers who support your argument. One would be Kant's idea that the Categories are the a priori abilities of the mind that enable both humans and squirrels to track phenomena and present them to the Understanding. Humans and squirrels have different Categories and therefore different perceptions of phenomena like "Blorts" and can reach different understandings. The other is William James's definition of truth as something that happens to an idea that we make true through its value. I am sure you know these ideas so just surprised you didn't avail yourself of them.