GENERALIZATION. Our experience of the world leads us to recognize not only great variety, but also numerous instances of agreement in the midst of the variety. We do not call the continuance of the same fact an agreement; it is only when, amid differ ence of accompaniment, we recognize a common feature, that our attention is awakened, and our mind interested. Sometimes the common feature in a number of varying objects is obvious and universally noticed; as when we identify the round form amidst all dis parities of size, color, and substance. At other times, the resemblance is so obscuied by the amount of difference, that it has lain for ages unperceived; the fall of a stone was never suspected, before the time of Newton, to have anything in common with the motions of the moon and planets. When we see the same property or effect repeated under great variety of circumstances and adjuncts, and when we indicate by a name or otherwise that this agreement exists, we are said to mark out a general or generalized property, or fact; while the individual instances are termed the particulars, on which the other is grounded.
To understand the full meaning of generalization, and the questions therewith con nected, we must advert to the distinction between two modes of the coration. In the one, we generalize an individual or isolated property—as roundness, TAlliteness, attraction, justice—and assign what we think the exact nature of the common feature thus singled out. A number of designations have been given to this process, according to the particular stage in the operation most specially taken into view; these are classi fidation, general notion, general term, definition, abstraction, concept or conception, idea. They all suppoe that we have a plurality of objects with agreeing properties, and that agreement lib been taken notice of, and embodied in such a form, that the mind can deal with it to the neglect of the points wherein the particular things differ• among themselves. They suppose, further. that we make no affirmation beyond what is implied in the identifying of so many differing objects—namely, that they do agree in the point in question. No other matter' for belief or disbelief is presented in the notion of roundness but that certain things have been compared, and have been found to agree in possessing that attribute. To attempt to form a general notion, or to mark a prop erty not attaching to anything in nature, is it pure irrelevance and absurdity; and'.
although by a bold stretch of imagination we might people the earth with chimerical objects, and find agreements among them, yet such generalities could not be introduced.: into any process of reasoning; it is presumed, that wherever a general property is speci tied, there arc things in nature having this property in company with the others that make up the total characteristics of each.
But the other kind of generalization introduces belief in a totally different shape. When instead of identifying a property, we identify a union or conjunction of distinct properties, it has to be seen not merely whether the common features are correctly ren dered in the general notion, but whether the. alleged place. thus, when we compare the sea-coasts all over the globe, we find, with some exceptions, that twice a day the sea advances and recedes on the shore: this fact we express by the gen eral name the tides. When, however, we go further, and note everywhere the coinci dence between the tides and the positions of the moon, and generalize that coincidence, we attain to a more complicated result. We are now called upon to believe not merely in the accurate correspondence of a general notion with the particular objects, but in the constancy of the conjunction between two distinct properties, so that the occurrence of one shall always count as evidence of the other. The different aspects of this higher operation have given rise to another series of designations, contrasting with those given ;Move for the simpler operation; these are induction, inductive generalization, conjoiued properties, affirmation, proposition, jndgment, law, order of nature. These all involve truth or falsehood, inasmuch as they all pretend to give us a positive assurance that wherever we find one thing we shall find some other thing present or absent, and be enabled thereby to anticipate our individual experience of the course of nature. A gen eral notion can often be expressed in a single word; the noun is the part of speech that names both particular objects and general notions. A general proposition is a complete thought. and requires a sentence for its enunciation; it involves the verb along with the noun. Heat is a notion, and so is light; but when we unite the two in the affirmation that heat is the cause of.light, we indicate something that is true or false, that may be proved or disproved, believed or denied.