That's exactly what I'm getting at! My idea here is strongly influenced by the thinking of Stanislaw Lem, who tackles this problem extensively in his works. He

That's exactly what I'm getting at! My idea here is strongly influenced by the thinking of Stanislaw Lem, who tackles this problem extensively in his works. He points out that it's very earth/bio-centric to assume that "life" on other planets would resemble in any way life on earth, and comes up with hypothetical life-forms that demonstrate this principle. If we come up with some abstract definition of "life", then it seems like "life" is a fundamental thing of which "life on earth" is just one particular manifestation. Following that, we imagine that there are other specific instances in the universe that implement that general principle. On the contrary, I think biological life is highly determined by its history and the geo-chemical particulars of earth itself, not by some fundamental principle. If we find extra-terrestrial "life" it's possible that the history and geo-chemical particulars of its evolution are so different from ours that we fail to recognize it as life at all.