A new approach to the evaluation of stability of chemical species is proposed. The main idea is to allow the species to conceptually interact via a special type of chemical reaction so that an equilibrium state is achieved. Additionally, the energies of the species are allowed to vary from their initial (standard) to their equilibrium values so that the energy change of any conceivable reaction at equilibrium is equal to zero. The equilibrium energies of the species are further evaluated using an optimization procedure similar to that of the least-squares method. A species is considered unstable if the difference between its initial and equilibrium energy is positive (the species releases energy). On the contrary, if the difference between the initial and the equilibrium energy of a species is negative, the species is stable (the species absorbs energy). This type of stability of species is referred to as the overall stability. Employing the response reactions (RERs) formalism, one shows further that the overall stabilities of the species may be partitioned into different types of contributions. In particular, it is shown that the conventional definition of stability of the species is just an appropriately normalized part of the overall stability.