I agree that
now a lot of it is subjective, because there is still a lot of research to be done, but my guess is that in 20 years, we will have more definitive answers on how animals learn. I think it will have wide implications for farm animals, dogs, and human education as well.
As you learn more, you may find that your opinions change. Some things are not purely subjective. I'm going to toot the book
Amazon.com: Canine Body Language: A Photographic...
because it is SUCH a great source of information on canine body language. This is a big reason why I feel more critical of Cesar than I did a few years ago, because I can see the dogs' stress reactions more clearly. It's also made a difference volunteering at a rescue and seeing a wide range of "bad" behavior (and we don't take aggressive dogs as a rule). Of course a little knowledge is a dangerous thing, and maybe as I learn more, I'll change my mind again. But I do feel a lot more confident about watching dogs in the park, or watching Thor, and getting a sense of how they feel and what they plan to do next.