Halleck says of Abstraction: "In the process of Abstraction, we draw our attention away from a mass of confusing details, unimportant at the time, and attend only to qualities common to the class. Abstraction is little else than centering the power of attention on some qualities to the exclusion of others." IV. _Generalization._ Arising from the stage of Abstraction is the stage of Generalization. _Generalization_ is: "The act or process of generalizing or making general; bringing several objects agreeing in some point under a common or general name, head or class; an extending from particulars to generals; reducing or arranging in a genus; bringing a particular fact or series of facts into a relation with a wider circle of facts." As Bolingbroke says: "The mind, therefore, makes its utmost endeavors to _generalize_ its ideas, beginning early with such as are most familiar and coming in time to those which are less so." Under the head of Abstraction we have seen that through Abstraction we may Generalize the various species into the various families, and thus, in turn, into the various sub-families. Following the same process we may narrow down the sub-families into species composed of various individuals; or into greater and still greater families or groups. Generalization is really the act of Classification, or forming into classes all things having certain qualities or properties _in common_. The corollary is that _all things in a certain generalized class must possess the particular quality or property common to the class_. Thus we know that all animals in the class of the _Carnivora_ must eat flesh; and that all _Mammals_ possess breasts from which they feed their young. As Halleck says: "We put all objects having like qualities into a certain _genus_, or class. When the objects are in that class, _we know that certain qualities will have a general application to them all_."