“Whatever implies being and nonbeing simultaneously is incompatible with the absolute possibility which falls under divine omnipotence. Such a contradiction is not subject to it, not from any impotence in God, but because it simply does not have the nature of being feasible or possible. Whatever, then, does not involve a contradiction is in the realm of the possible with respect to which God is omnipotent. Whatever involves a contradiction is not within the scope of omnipotence because it cannot qualify for possibility. Better, however, to say that it cannot be done, rather than God cannot do it.” (T. Aquinas Summa Theologica p. 163-164 , Volume I, ques. 15 ans. 3)