I assume we agree that we are observing real things in the real world in this discussion of 'life'. Can we not generate a set of objective properties or criteria based on our empirical observation?
When I watch a magician do a magic trick, I am "really" watching a magician perform a "real" magic trick. I am "real", the magician is "real", the trick is "real", and the different experience each of us has of that trick's happening is "real". In fact, NONE OF IT WAS
UNREAL. The magician really is a magician, and the trick really is a trick, and I really was fooled by it even though I wasn't really fooled by it because I knew it was a trick.
I say all this to try and get you to understand that reality is all there is. Misperceived, misunderstood, mistaken, mislabeled, or whatever else;
it's all "real". There is no "unreality" vs "reality". A theory about reality does not exist in some realm apart from the reality it's about until it's "proven to function" by some physical mechanism. The sound of a train horn does not exist apart from the ear that hears it. They are conjoined phenomena. In fact all of existence is a conjoined phenomenon. All the "parts" of it that we perceive are only being perceived as 'parts' in relation to all the other 'parts' of it that we perceive in relation ... you get the idea. In truth, it's just one big complicated phenomenon taking place in an endless sea of 'nothing else'.
Once we understand this: that any 'knowledge' (of existence) we can seek is
contextual, we can begin to see what the philosophers are debating, and why. They are debating the contextual validity of a proposed truth-claim against those of other proposed truth-claims. Because philosophers understand that "truth" is a moving target: that it's contextually dependent. And the contextual possibilities are endless, given that the complexity of existence is endless.