Color, shape, size, mental qualities, habits of action--these are some of the qualities first observed in things and abstracted from them in thought. Redness, sweetness, hardness, softness, largeness, smallness, fragrance, swiftness, slowness, fierceness, gentleness, warmness, coldness, etc.--these are abstracted qualities of things. Of course these qualities are really never divorced from things, but the mind divorces them in order to make thinking easier. An authority says: "Animals are incapable of making abstractions, and that is the reason why they cannot develop formal thought. * * * Abstract thought is identical with rational thought, which is the characteristic feature of the thought of speaking beings. This is the reason why abstract thought is upon earth the exclusive property of man, and why brutes are incapable of abstract thought. The process of naming is the mechanism of abstraction, for names establish the mental independence of the objects named." The processes of abstraction depend upon attention--concentrated attention. Attention directed to the qualities of a thing tends to abstract the qualities in thought from the thing itself. Mill says: "Abstraction is primarily the result of attention." Hamilton says: "Attention and abstraction are only the same process viewed in different relations." Cultivation of the power of abstraction means principally cultivation of attention. Any mental activity which tends toward _analysis_ or separation of a thing into its parts, qualities, or elements will serve to cultivate and develop the power of abstraction. The habit of converting _qualities_ into concepts is acquired by _transforming adjective terms into their corresponding noun terms_. For instance, a piece of colored candy possesses the _qualities_ of being round, hard, red, sweet, etc. Transforming these adjective qualities into noun terms we have the _concepts_ of roundness, hardness, redness, and sweetness, respectively. COMPARISON. The third step in conception is that of _comparison_, in which the qualities of several things are compared or examined for likenesses and differences. We find many qualities in which the several things differ, and a few in which there is a likeness. Classes are formed from resemblances or likenesses, while individuals are separated from apparent classes by detection of differences. Finally, it is found that separate things, while having many points of difference which indicate their individuality, nevertheless have a few points of likeness which indicate that they belong to the same general family or class. The detection of likenesses and differences in the qualities of various things is an important mental process. Many of the higher thought processes depend largely upon the ability to compare things properly. The development of attention and perception tends to develop the power of comparison. CLASSIFICATION OR GENERALIZATION.