the predicate has been objected to for this reason, among others, that the propositions which it vindicates are so awkward and unnatural, that they seem "got up for the purpose of seeing what one can do." Perhaps so; and yet the objection is an idle one. For if there are occasions when we must think affirmative Judgments with universal predicates, and negative Judgments with particular ones, the Logician's first duty is to express this fact, however awkward and even ludicrous such expression may seem.

CHAPTER IV.

THE DOCTRINE OF CONCEPTS.

1. Their Quantity; 2. Their Quality; 3. Their Relation; 4. Their Definition and Division.

A

CONCEPT is a combination, or a reduction to unity in Thought, of those elements and qualities of the objects which we are thinking of, whereby they are distinguished from all other objects, and especially from those which, in other respects, are most similar to them.* These distinguishing attributes, which are the elements of the Concept, are called its Marks; for through them the objects of Thought are determined, or known to be what they are, and discriminated from what they are not. The word, or General Term, which is the appellation of the Concept, is, consequently, the Common Name of all the objects that are included under it. It is a convenient use of language, (though the words are sometimes applied in a different manner,) to say that the word or Name connotes

*The words Concept and Notion, often used as synonymes, are perhaps best distinguished etymologically; - Concept (con-capere) as the grasping up together of a plurality of attributes into one Thought; Notion (noscere notis, to know an object by its Marks), as the taking note of the several Marks or characteristics of an object. The meaning of Notion might, perhaps, be conveniently limited to the apprehension of any single Mark (nota), while Concept signifies the comprehension of all the attributes which are characteristic of a certain class of things. Thus, I have a Notion of each of the Marks, cold-blooded, vertebrated, animal, breathing by means of gills, and living in the water, taken singly; and I have a Concept of them taken together, as the characteristic Marks of a Fish, or of the whole class of Fishes. As thus limited, Notions are a subordinate class of Concepts.

the attributes or Marks which make up its signification,* and denotes the individual things contained under it which possess those attributes. Thus, the name Man connotes biped, two-handed, rational, animal, and denotes all individual men and classes of men.

It has already been explained, that a Concept is not necessarily the Thought of an actual, but only of a possible, class of objects; that is, its name may actually denote only one thing, as, for example, the one animal, just discovered, of a species hitherto unknown. Hence, Esser was led to define a Concept as "the representation of an (one) object through its distinguishing Marks." But even in this case, the representation, in order to be a Concept, must be a partial representation; that is, it must represent, not all the Marks, but only the distinguishing Marks. Thus it becomes the representative of a possible class or plurality of things; if other specimens should be subsequently discovered possessing these distinguishing Marks, the Concept would include them also. It is only when the object is immediately presented before us either by the Senses or the Imagination, so that we have a Presentation or Intuition of it, as one whole, with all its

"As these qualities or modes are only identified with the thing by a mental attribution, they are called attributes; as it is only in and through them that we say or enounce aught of a thing, they are called predicates, predicables, and predicaments, or categories (these words being here used in their more extensive signification); as it is only in and through them that we recognize a thing for what it is, they are called notes, signs, marks, characters; finally, as it is only in and through them that we become aware that a thing is possessed of a peculiar and determinate existence, they are called properties, differences, determinations. As consequent on, or resulting from. the existence of a thing, they have likewise obtained the name of consequents. What in reality has no qualities has no existence in thought, — it is a logical nonentity; hence e converso, the scholastic aphorism, non-entis nulla sunt predicata. What, again, has no qualities attributed to it, though attributable, is said to be indetermined; it is only a possible object of thought." - HAMILTON, Lectures on Logic, Am. ed., p. 55.

attributes, that its Name is a Proper Name strictly so called; for if it is present only in Thought, our representation of it is necessarily partial, as not including all its Marks, and its Name is then virtually Common, as the designation of a possible plurality of things. Thus, if I am contrasting in Thought two historical characters, as Cesar and Pompey, these two names to my conception become General Terms, as several individuals may each possess the few Marks which, for the purposes of this contrast, I attribute to those two old Romans. Gray's affecting lines may be attributed to any churchyard: —

"Some mute inglorious Milton there may rest,

Some Cromwell, guiltless of his country's blood."

Still further; not merely may a Concept actually denote only one thing, it may actually connote only one Mark. But here, as before, there is a possible plurality in actual unity. Thus, in the present state of my knowledge, my Notion or Concept of red color may be absolutely simple,that is, it may have but this one Mark of redness. But additional acquaintance with the science of Optics would teach me that this red color is an element of white light, and that it has a certain degree of refrangibility, by virtue of which its position in the solar spectrum is at one end of the scale. Here are three additional Marks of red color. In like manner, every Concept, though actually simple, must be regarded as containing a possible plurality of Marks. I say, it must be so regarded; for every Concept must denote some existing object, -existing, that is, either really or potentially; and no such object can be conceived of except as possessing a possible plurality of Marks. For every object can be conceived to be what it is, only by discriminating it from several things which it is not; and such discrimination is possible only through a plurality of attributes.

This will be more evident, if we consider for a moment the various kinds of Marks by which one Concept may be distinguished from another. The following enumeration of them, which might be much enlarged, is taken in great part from Esser.

3.

Marks are divided,-1. Into affirmative and negative, according as we know through them either what the object is, or what it is not; thus, rational is an Affirmative, imperfect a Negative, Mark of Man. 2. Into internal and external, according as the Mark is attributed to the object either in and for itself, or on the ground of the relation in which it stands to some other object; thus, biped is an Internal, Father or Son an External, Mark of Man. Into permanent and transitory, according as they are always, or only sometimes, found in the object; thus, metallic is a Permanent, hot is a Transitory, Mark of Iron. 4. Into peculiar and common, according as they belong to these only, or also to other objects; thus, right-angled is a Peculiar, plane-figure is a Common, Mark of a Square. 5. Into essential or necessary, and accidental or contingent, according as they can, or cannot, be separated from the object; thus, rational is an Essential, learned an Accidental, Mark of Man. 6. Into original or immediate, and derivative or mediate, according as they are either Marks of the thing itself, or only Marks of other Marks of it; thus, free-willed is an Original, able to compute by numbers a Derivative, Mark of Man, the latter being only a consequent or Mark of rationality.

We gain another view of the elements of a Concept by dividing them into,- 1. Kinds of Existence; 2. Qualities, or Modes of Existence; and 3. Relations, or Forms of Intermediate Existence.

First, in order to conceive, we must conceive something,i. e. some being or existence, which, as an object of Thought, may be distinguished from other things, and