Example: I recall the physical sensations of a chill, and live it over in my mind, so that I can accurately describe how a chill feels to me, though I can but surmise how one feels to you. _Inorganic memory_ is the mind's reproduction of its own reactions in the past. Example: Myself having a chill, how I acted; what I thought and my emotions during that chill. _Ideation_ is the mind's grouping of percepts by the aid of memory, to form concepts. Example: I perceive color, form, mouth, eyes, nose, chin, etc. These percepts I combine as a result of past experience (memory) to form my concept, _face_; and the process of combining is ideation. _Concepts_ are mental representations of things or qualities, _i. e._, of object or quality percepts. We might say that the percept is the mind's immediate image of a thing or quality, and the concept is the result of the storing up and grouping and recombining of percepts. Thus a lasting mental picture is secured; and my idea of horse, for instance, is so clear and definite a thing in my mind that if I should never again see a particular horse, I should yet always be able to think accurately of a horse. Concepts are of two kinds--concrete and abstract. A _concrete concept_, or concrete idea (for concept and idea are interchangeably used), is an idea of a particular object or quality. Examples: This wine-sap apple (object concept). This sweet orange (quality concept). An _abstract concept_, or abstract idea, is a mental reproduction of a quality or an object dissociated from any particular setting or particular experience. Abstract ideas are of two kinds. We speak of them as _abstract object concepts_ and as _abstract quality concepts_. An _abstract object concept_ we might call a generalized idea, an idea comprehending all objects having certain things in common. Example: My idea of animal includes many scores of very different individual animals, but they all have bodies and heads and extremities. They all have some kind of digestive apparatus; they breathe, and can move. An _abstract quality concept_ is easier to think than to explain. It is as though the mind in considering a multitude of different objects found a certain quality common to many of them, and it "abstracted," _i. e._, drew this particular quality, and only this, from them all, and then imagined it as a something in itself which it calls _redness_, or _whiteness_, or _goodness_. Thereafter, whenever it finds something like it anywhere else again it says, "That is like my redness." So I call it "red." In other words, consciousness thereafter can determine in a newly discovered object something it knows well merely because that something corresponds to a representation which experience and memory have already formed.