Well, I guess it's all a matter of definitions and agreeing on those definitions.
Property is a social construct. The requirements for property are also a social construct. I would assume for most people it's proof of work, but not for everyone. Somehow we agree on a definition. Violating it then becomes theft.
Likewise, stealing could be defined as anti-life. It's corrosive to society and indirectly makes existing life harder, even destroying it if taken to the extreme, but you could also argue that such destruction makes room for new life to emerge and is ultimately pro-life. Again, a question of definitions.
There is an absolute reality, but there is also a whole other world of our collective imagination that has never really touched reality but keeps telling us stories about reality, how it ought to be, shaping it in the process. As Nietzsche put it: "The mind is the life that cuts into life itself."
I stole my old avatar, by the way. The current one too. Well, actually I just linked them, but that's a matter of definition again, I guess. lol