But that's kind of my point - we do have evidence. As much as we have for humans, at least

Koko the gorilla is what made me start to question all of this back in grade school. This gorilla learns sign language, and is shown picture books with cats. She asks for a cat for Christmas, despite never having actually seen one. They give her a toy one and she gets angry.

Months later, they bring in kittens. She picks the tailless tabby and names it "all ball". It was her pet all its life, she would take care of it and even told the keepers it had ear mites

On a foggy December morning, one of the assistants told me that Ball had been hit by a car. He had died instantly. I was shocked and unprepared. I didn’t realize how attached I had grown to Ball, and I had no idea how the news would affect Koko. The kitten meant so much to her. He was Koko’sbaby. I went to Koko at once. I told her that Ball had been hit by a car; she would not see him again. Koko did not respond. I thought she didn’t understand, so I left the trailer.

Ten minutes later, I heard Koko cry. It washer distress call—a loud, long series of high-pitched hoots. I cried, too.

Three days later, Koko and I had a conversation about Ball. “Do you want to talk about your kitty?” Iasked. “Cry,” Koko signed.“ Can you tell me more about it?” I asked. “Blind,” she signed. “We don’t see him anymore, do we? What happened to your kitty?” I asked. “Sleep cat,” Koko signed. A few weeks later, Koko saw a picture of a gray tabby who looked very much like Ball. She pointed to the picture and signed, “Cry, sad, frown.”

Koko described herself as "fine gorilla person", she painted and joked and understood mortality.

Why is Koko special? Because she was interested in communicating, and so was her keeper. That was decades ago... Back when we rarely accepted animals were even sentient, let alone sapient

I've watched a video where a dog described it's dreams, and one where a cat lied and negotiated for a treat before being convinced over the course of minutes to willingly take it's medicine to make the "hurt go bye".

My childhood dog was well behaved, so we'd let him in or out when he scratched on the door. We stopped paying attention... We only caught him exploring the suburbs when a neighbor called us. One day we were driving and saw him miles from home, so we followed... He kept to the sidewalks, avoided people, and looked before crossing the street. So we let him have his secret life, and he never got into any trouble... We wouldn't have known otherwise, because he timed his adventures well

My mom's dog used to watch dog shows, and smiled wide when I put a medal around her neck jokingly... Not when I put my keys around her neck, just the medal - I did ABACAB testing, just the medal got that reaction.

You can explain away all these things, or you can entertain the idea. Maybe Koko was the exception or my mom's dog just thought the medal was pretty, or maybe she dreamed of winning a dog show.

We can't even philosophically nail down sapience, and yet we don't have a second Koko... Because we barely try to meet them where they are, and dismiss every success as an anomaly

The evidence is everywhere, we just seem to ignore it

It seems weird to me that the null-hypothesis there should be that dogs are non-sapient. It seems to be common for scientists to default on non-existence until evidence of existence is found. But in some situations existence and non-existence should have equivalent weights. In the field of mathematics, the existence of a thing can be logically equivalent to the non-existence of another thing, and we dont know which of the two exists, but we cant default to assuming neither of the two. Science is a bit different from pure mathematics though, but im not sure in what ways.