  The Ising model, in presence of an external magnetic field, is isomorphic to
a model of localized interacting particles satisfying the Fermi statistics. By
using this isomorphism, we construct a general solution of the Ising model
which holds for any dimensionality of the system. The Hamiltonian of the model
is solved in terms of a complete finite set of eigenoperators and eigenvalues.
The Green's function and the correlation functions of the fermionic model are
exactly known and are expressed in terms of a finite small number of parameters
that have to be self-consistently determined. By using the equation of the
motion method, we derive a set of equations which connect different spin
correlation functions. The scheme that emerges is that it is possible to
describe the Ising model from a unified point of view where all the properties
are connected to a small number of local parameters, and where the critical
behavior is controlled by the energy scales fixed by the eigenvalues of the
Hamiltonian. By using algebra and symmetry considerations, we calculate the
self-consistent parameters for the one-dimensional case. All the properties of
the system are calculated and obviously agree with the exact results reported
in the literature.
