  We propose a novel definition of life in terms of which its emergence in the
universe is expected, and its ever-creative open-ended evolution is entailed by
no law. Living organisms are Kantian Wholes that achieve Catalytic Closure,
Constraint Closure, and Spatial Closure. We here unite for the first time two
established mathematical theories, namely Collectively Autocatalytic Sets and
the Theory of the Adjacent Possible. The former establishes that a first-order
phase transition to molecular reproduction is expected in the chemical
evolution of the universe where the diversity and complexity of molecules
increases; the latter posits that, under loose hypotheses, if the system starts
with a small number of beginning molecules, each of which can combine with
copies of itself or other molecules to make new molecules, over time the number
of kinds of molecules increases slowly but then explodes upward hyperbolically.
Together these theories imply that life is expected as a phase transition in
the evolving universe. The familiar distinction between software and hardware
loses its meaning in living cells. We propose new ways to study the phylogeny
of metabolisms, new astronomical ways to search for life on exoplanets, new
experiments to seek the emergence of the most rudimentary life, and the hint of
a coherent testable pathway to prokaryotes with template replication and
coding.
