99. In the idea of every substance is contained the idea of being; what does not exist cannot be a substance. Inasmuch as we conceive being as a reality, as opposed to nothingness, the idea of being belongs both to God and to creatures: God is, that is to say, God is a real thing, not nothing. But if from this general idea, such as we conceive it in opposition to nothingness, we pass to its realization in objects, to the manner of its application, so to speak, we find all the difference that there is between the contingent and the necessary, the finite and the infinite. Although we do not intuitively see the infinite being, nor the essence of finite beings, still we have evident knowledge that the word _being_ applied to the infinite means something very different from what it does when applied to the finite. 100. In the idea of substance is also contained the idea of something permanent; this permanence belongs also to God: the infinite being is essentially permanent. 101. In the substances around us we find this permanence combined with the succession of the modifications which affect them; these changes are impossible in God. The relation to modifications is a characteristic quality of finite substances. 102. Substances are not inherent in others as modifications are inherent in them; this non-inherence also belongs to the divine substance. 103. Substances must contain something which exempts them from the necessity of inherence and raises them above the things which so rapidly succeed each other, and in their existence always need another to sustain them; this perfection is found in the divine substance which is being essentially, the fountain of perfection. 104. It follows from this analysis that all the perfection contained in the idea of substance may be applied to the infinite being; and that all that is contained in this idea which cannot be applied to this being is what implies negation or imperfection. CHAPTER XIV. AN IMPORTANT REMARK, AND SUMMARY. 105. When we say, that a substance is a being subsisting by itself, we do not mean that it is a being which has absolutely no need of another for its existence. To confound these two things would produce a frightful confusion of ideas, and is itself produced by a not less frightful confusion of the relation of cause and effect with the relation of substance and accidents.