The absence of spontaneous blending of an amorphous polymer with a liquid, when their solubility parameters coincide, is explained by a specific feature of the polymer supermolecular skeleton. The process of spontaneous blending requires dissolving the supermolecular skeleton and takes place only under the sufficient entropy-donor activity of the Liquid. The lack of this activity rules out the spontaneous process. However, the compatibility does occur via indirect pathway when stimulating a proper excitation or disintegration of a supermolecular carcass.