Before revision: Miller's central thesis is that the systems in existence at all eight levels are open systems composed of critical and mutually-dependent subsystems that process inputs, throughputs, and outputs of various forms of matter– energy and information.
After revision: Miller's central thesis is that the multiple levels of living systems (cells, organs, organisms, groups, organizations, societies, supranational systems) are open systems composed of critical and mutually-dependent subsystems that process inputs, throughputs, and outputs of energy and information.