The concept of the basicity of chemical compounds is analyzed and shown to be of a relative character; that is, it is demonstrated that the degree to which the basicity of a component is manifested depends on the difference between its basicity and that of a second component, with which it is interacting. The applicability of the concept of electronegativity to evaluating the basicity of simple and compound oxides is shown to be very limited. The possibility and method of constructing semiempirical scales of basicities for quantitatively assessing the relative basicities of oxides, with a view to predicting the enthalpies of formation of compound oxides, are discussed.