  One of the basic questions of solar research is the nature of the Sun. We
show here how the plasma nature of the Sun leads to the self-generation of
solar activity. The release of magnetic, rotational, gravitational, nuclear
energies and that of the gravity mode oscillations deviate from uniformity and
spherical symmetry. Through instabilities they lead to the emergence of
sporadic and localized regions like flux tubes, electric filaments, magnetic
elements and high temperature regions. A systematic approach exploring the
solar collective degrees of freedom, extending to ordering phenomena of the
magnetic features related to Higgs fields, is presented. Handling solar
activity as transformations of energies from one form to another one presents a
picture on the network of the energy levels of the Sun, showing that the Sun is
neither a mere "ball of gas" nor a "quiescent steady-state fusion-reactor
machine", but a complex self-organizing system. Since complex self-organizing
systems are similar to living systems (and, by some opinion, identical with
them), we also consider what arguments indicate the living nature of the Sun.
Thermodynamic characteristics of the inequilibrium Sun are found important in
this respect and numerical estimations of free energy rate densities and
specific exergies are derived.
  KEY WORDS solar physics, degrees of freedom, self-organizing complex systems,
non-equilibrium thermodynamics, astrobiology
  CLASSIFICATION PACS: 01.70.+w, 96.60.Rd
