Classification, in what sense arbitrary.

It will readily be seen that classification from one point of view, will run directly across and back of that which is formed from another. How distinct and opposite, for example, will classification be which is founded in view of some one abstract quality, such as redness, from that which is based upon general resemblance, and formed under a general conception. Equally distinct and unlike either of the others will be the arrangement of objects, which are classed together under some pure rational conception.

For these reasons classification has, by many been regarded as perfectly arbitrary. It is true, that we are at liberty to adopt either of the principles of classification above described we please. In this respect, the process is perfectly arbitrary. If we classify at all, however, we must adopt one or the other of the forms under consideration, no other forms being conceivable. When we have selected our principle also, the subsequent arrangement of objects in conformity to it is necessary. In very important respects, therefore, classification has its laws, which are by no means arbitrary.

Genera and Species.

In the process of classification, objects are ranged together as genera and species. Thus we have the genus tree, and the different classes, or species of fruit-bearing and forest trees, ranged under it. A species also is often itself a genus relatively to particular and distinct classes belonging to that species. If fruit-bearing be assumed as the genus, then we have the apple, plum, peach, cherry trees, &c., ranged as species under this generic term. The illustration might be extended indefinitely, from the highest to the lowest forms of genus and species. Our present concern is with the principle on which objects are thus classed. It is that to which we have frequently referred in this Chapter, the idea of resemblance and difference. The genus is formed on the perception of remote resemblances. Species under the genus are formed on the perception of important differences; while objects are classed under the species, on the perception of resemblances more near and special. Thus the genus tree is formed on the perception of qualities common to all trees. The species fruit-bearing and forest trees, are separated from each other, on the perception of important differences, each

species being formed on the ground of resemblances more near and particular than those designated by the general term tree.

In illustration of the process in which classes, as genus and species, are formed, we will take the case of the child. A certain object stands near the paternal mansion, which he has learned to designate by the term tree. By and by he sees another object resembling this in all important particulars. Here, he says, is another tree. In his mind they are distinguished as greater and less, and in respect of loca tion. Here is the obscure development of the ideas of genus and species. At length, however, he perceives a tree differing in very important particulars from either of the others. He now asks the question, what kind of tree is this? The answer is, we will suppose, a maple tree. Then the inquiry arises, what tree is that which stands near the house? He is told that it is an elm tree. He has now the idea of the genus tree, formed on the perception of common qualities, and of two species, separated from each other on the perception of important differences. All trees subsequently perceived, presenting similar resemblances and differences, will be separated and arranged accordingly. As other trees, differing from either of these, are perceived, they will be separated and classed in a similar manner. Throughout the whole process, one idea guides the mind, that of resemblance and difference.

GENERALIZATION.

But few words are requisite in the explanation of the mental process called Generalization. A general fact is a quality common to every individual of a given class. It may be peculiar to that class; or, while it belongs to each individual of the class, it may appertain to individuals of other classes.

Rules in respect to Generalization.

1. No fact must be assumed as general, which does not belong to each individual of the class to which it is referred. 2. No general fact must be assumed as peculiar to one class, which, though strictly general in respect to that class, nevertheless appertains to individuals of other classes.

3. No fact must be assumed as general without a sufficient induction of particulars, to remove all doubt in respect to the question whether it is, or is not, a general fact.

The Term General sometimes used in a limited sense.

In common usage, a fact is called general, when it belongs to a majority of the individuals of a certain class. In such a case, its existence in connection with an individual of the class is only probable. Great injury is often done to individuals in the application of facts of this kind.

GENERAL TERMS.

In the progressive developments of mental science, the question has long been agitated among philosophers, whether when we use general terms, such as man, animal, there are ideas in the mind, and objects in the universe around us, corresponding to these terms, or whether they are mere terms, without corresponding ideas and objects. In respect to such terms, three distinct theories have been formed by as many different sects of philosophers.

Theory of the Realists.

The first was maintained by a particular class of the schoolmen, and deduced from certain principles, real or supposed, maintained by Aristotle. The theory was this: There exists in nature, not only individual substances, but certain essences, corresponding with the general ideas which exist in the mind. When, for example, we use the term man, it was maintained that there exists in the world around us a certain essence, which is found in no individual of the species, and which exists in connection with no individual, but which corresponds with the idea in the mind, which idea is designated by the above term. So of every other general term. The sect of philosophers maintaining this theory was called Realists. Their dogmas have been long since exploded.

Theory of the Nominalists.

Another theory directly opposed to the above, was maintained by a sect of philosophers which arose in the eleventh century. "According to those philosophers," says Mr. Stewart, "there are no existences in nature, corresponding to genral terms; and the objects of our attention, in all speculations, are not ideas, but words." This sect was called the Nominalists. As there are no existences in nature, according to this sect, corresponding with general terms, all our specula

tions and reasonings, but for our knowledge of such terms, must be confined to individuals. The following from Mr. Stewart, who was an avowed Nominalist, will illustrate the meaning of the above remarks, as well as show their correctness. "It has been already shown, that without the use of signs, all our knowledge must be necessarily limited to individuals; and that we should be perfectly incapable, both of classification, and general reasoning." If the author means that without the use of signs, we should be unable to communicate our thoughts to each other, what he says is a mere truism, which is no less applicable to individuals. But if he means, as he evidently does, that without the use of signs, we could not reason upon general subjects, I reply,

1. That the existence of the names themselves implies the previous process of reasoning and classification, to which he supposes these terms give birth. A class must first be formed, and a judgment affirmed, before any particular term can be chosen to designate them. Now as the process of classification gives existence to general terms, which processes must always be anterior to the terms themselves, the mind must possess the power of classification and general reasoning, in the absence of such terms. The mistake of the author consists in changing the order of sequence, putting the effect for the cause.

2. Individuals have been known who have lost entirely. all recollection of general terms, and who have yet retained the power of classification and reasoning upon general subjects unimpaired.

3. If our reasonings upon general subjects respect not ideas, nor things, but words merely, then all general conclusions must be absolutely useless in all the concerns of real life. In such circumstances, we have to do with realities exclusively, and shall find no place for conclusions in respect to abstractions, or rather in respect to the relations of abstractions which have no existence in nature.

4. The fact, that general terms are always defined by a reference to individuals, shows clearly, that there are, in such individuals, realities corresponding to the terms employed.

Theory of the Conceptualists.

We come now to notice the doctrine of the sect denominated Conceptualists, or Notionalists. According to the doctrine of this sect, a general term, when considered objec

tively, denotes those qualities which exist alike in all individuals of a given class-when considered subjectively, it designates the conception of these qualities in the mind. Instead of there being no existences in nature, according to the doctrine of the Nominalists, corresponding to general terms, they maintain, that there is in every individual of a given class, that which corresponds with those terms. The doctrine of this sect, as will be seen, is equally removed from that of the Realists and Nominalists both. That the doctrine of this sect is correct, and the only correct view of the subject, is evinced, because :

1. When the mind affirms of any particular object, as soon as perceived, that it is a man, a horse, an animal, such affirmation supposes the existence in the mind of a certain notion, or conception of a given class of objects, and the perception of the agreement of the given object, with that conception. It can be accounted for upon no other suppo

sition.

2. Every person, when he appeals to his own Consciousness, knows, that when using general terms, he is designating conceptions really existing in his own mind, conceptions pertaining to real qualities of classes of objects existing around him.

3. General terms are always defined by a reference to the qualities existing in individuals of a given class, and no definition is allowed to be correct, which does not designate the qualities common to the whole class to which it is applied.

4. General conclusions, when correct, must be applicable to all the individuals of the particular class to which they are applied. This shows that such conclusions are based upon the conception of the common qualities of each individual of the class.

UNDERSTANDING AND JUDGMENT DISTINGUISHED.

Having explained the process of abstraction and classifi cation, it now remains to compare this process with the action of the Understanding. A moment's reflection will convince us, that this process, and that of forming notions, are entirely distinct from each other, and must be referred to functions of the Intelligence equally distinct. To form a notion of A and B, and to affirm that they agree or disagree, are intellectual operations, entirely distinct from each other. The former process is called conception; the latter is called