The concept of quasi-average introduced by N. N. Bogoliubov for describing the states of many-particle systems with spontaneously broken symmetry (superfluid liquids, superconductors, crystals, etc.) is generalized so that the fields introduced into the initial Hamiltonian for breaking its symmetry are not presumed to be given from outside, but are determined by the properties of the physical object itself and can be found by solving the system of equations in the self-consistent field approximation.