130. When the understanding proceeds by indeterminate conceptions, its principal object seems to be _being_ in its greatest universality. This is the radical and fundamental idea, round which all other ideas are grouped. From the idea of being springs the principle of contradiction, with its infinite applications to every class of objects; from it also flow the ideas of substance and accidents, of cause and effect, of the necessary and the contingent, and every thing contained in the science of ontology, called for this very reason _ontology_, or the science of being. 131. There is nothing in those conceptions which express the general relations of all beings, to characterize them until they quit their purely metaphysical sphere and descend into the field of reality. In order to be able to conceive of a real being, we require it to be presented to us with some property. Being and not-being, substance and accidents, cause and effect, are, when combined with something positive, highly fruitful ideas; but taken in general, with nothing determinate assigned to them, they do not offer us any existing, or even possible object. 132. The idea of being presents us that of a _thing_ in the abstract; but if we would conceive of this as existing or as possible, we must imagine this thing to be something with characteristic properties. Whenever we hear an existing thing spoken of, we instinctively ask what it is, and what is its nature. God is essentially being, is infinite being; but nothing would be represented to our mind were we to conceive of him only as of being, and not also as intelligent, active, free being endowed with all the other perfections of his infinite essence. 133. The idea of substance offers us that of a permanent being, which does not, like a modification, inhere in another. This idea, taken in its generality without other determination than that added to the idea of being, by that of subsistence, offers us nothing real or realizable. Permanence in general, subsistence by itself, non-inherence in a subject, do not suffice to enable a substance to exist or to be possible; some characteristic mark, some attribute is also needed, as corporeal, intelligent, free, or any other you please, to determine the general idea of substance. 134. The same may be said of the idea of cause, or productive activity. An active thing, in general, offers us nothing either real or possible. In order to conceive an existing activity, we must refer to a determinate activity; the idea of acting, or of being able to act, in general, does not suffice; we must represent it to ourselves, as exercising itself in one way or another, referring to determinate objects, producing, not beings in general, but beings having their own characteristic attributes. True, we do not need to know what these attributes are; but we do need to know that they exist with their determinateness.