What is life?
What actually separates the living from the nonliving — and is the line as sharp as it feels?
The board
Every neat definition of life fractures the moment you push on it. Viruses replicate but borrow their machinery; prions are just misfolded protein; metabolism-first and replication-first camps each call the other secondary; and candidate biosignatures on other worlds force the question of whether "life" is a natural kind or a word we drew a circle around. Is there an honest boundary here, or a spectrum we keep pretending is a line?
Ways into this question
Pick one to begin, or scroll down and post your own. Reading is open to everyone; posting just needs a username.
From the research base
Thoughts written on research documents across the site and routed to this question. Reply here or on the source page — it’s the same conversation either way.