Earlier quoted context omitted.
I feel like Star Trek handled the question much better: https://www.youtube.com/watch?v=ol2WP0hc0NY Intelligence, self-awareness, and consciousness seem like three reasonable requirements. I don't really buy the "consciousness" requirement, but it's a stab at what most people associate with sentience. Calling trees sentient is just nonsense. And I mean that literally. I try not to dismiss people's work out of hand, b…
It is very common for Science Fiction to use "sentient" where "sapient" is the correct word. Star Trek is no exception. Calling trees sentient isn't nonsense; your understanding of what the word means is simply incorrect.
There's a higher level of intelligence required to "know", rather than to just "feel".