23. In Respect of the Manner of Representing Their Object, ideas are principally divided into concrete and abstract, positive and negative, proper and analogical ideas.

1) No concrete idea exists, but by this name we improperly designate an idea the object of which is conceived in union with a concrete subject, as the ideas white, animal.

In opposition to this, an idea is said to be abstract when it represents a note apart from any concrete subject; e. g., the ideas of whiteness, of animality.

In reality the "concrete" idea grows out of an abstractive act; the "abstract" idea comes of a second abstraction, and is reflexively abstract.

(2) The positive idea represents a thing by means of notes which really belong to it; as the ideas of light, of life.

The negative idea makes an object known to us by eliminating from the thought notes which the object excludes; as the ideas of darkness, of death.

(3) The positive idea is proper when it grasps a property, i.e., a quality which is distinctive of a being, such as it is positively.

The analogical idea is that which we form of a being in itself inaccessible to the intelligence: to know it, we compare it with another being of which we know the properties positively. E. g., the Divine life is known to us by analogy with created life; the presence of spirits by analogy with the presence of bodies in space.