I was telling my friend today that i was starting research on how to set up an octo tank and care for a ceph. She immediately got defensive saying that i shouldn't. Her argument is that keeping an octopus (or any other live animal, which she later changed to "smart" animal) in a tank instead of the ocean is not right because we have no idea whether they are okay and happy with being captive. I told her that any cephs are given plenty of tank space (i mentioned 50 gallon absolute minimum for smallest octo) and she said "yeah but thats only 50 gallons compared to what they would experince in the ocean." I kept telling her that we have lots of indicators of happy cephs like the span of their life and their activity and she kept saying that all those indicators still can't make us certain whether or not they are happy being captive. In addition she said that the span of their life doesn't mean they "enjoyed" their life as they could have in the ocean, To which I spoke about how they may be smart but do not operate on the same level as humans. I told her she was giving them too much humanity and how even though they are smart it's not as if they "long for the ocean" or stuff like that. They may be good problem solvers and tool users but it's not as if they think existentially. At this point it was no point in continuing to talk. She raised her voice and said "why can't they have humanity!" and i was done. She is a really smart person, but when she gets worked up she just raises her voice and acts contrarian so she isn't even processing what i was telling her. I ended it with "If you are going to just disregard any scientific, reproducible indicators of the octo enjoying its habitat just as much as it would in the ocean such as the length of its life, its activeness, its sociability, and so on then you clearly have no respect for any scientific achievement by animal behavioralists in the past hundred years." Later in the night I continued by telling her that by the same logic she used earlier, we can't know if any animal is okay being with the person that cares for them but she wasn't listening. My question is this: How can we know for sure whether or not captive. My friend and I are both Physicists/Electrical Engineers, so we aren't dumb but neither of us know super much about animal behavior. I have done some reading on cephs but she kept using the argument that "we can't know for sure." I know that we have some amazing biologists here on Tonmo. So can any answer this question?