Primary and secondary qualities - Locke, book 2d, chap. 8, sec. 9, 10, 18, 24; Reid, Essay 2d, ch. 17; Cousin, ch. 6.

Sir W. Hamilton, Dissertation supplementary to Reid; note D.

Laws of Perception-Reid, Essay 2d, ch. 1, 2.

The credibility of the evidence of perception demonstrated-Sir W Hamilton's Dissertation on Common Sense. Note A, as above.

SECTION XI. OF CONCEPTION.

THE subject of conception is, in its origin, so intimately allied to perception, that, although it enters as a constituent element into almost every act of the mind, there seems a propriety in treating of it here.

The word conception has already frequently occurred in the preceding pages. It is proper that it should be more definitely explained.

Conception has been defined as that act of the mind in which we form a notion or thought of a thing. To this, however, it has been objected, that the word notion or thought in this place means the same as conception, and that we might with the same propriety reverse the definition, and say that the having a notion of a thing was the forming a conception of it. There seems to be force in this objection. The fact is, that a simple act of the mind is incapable of definition. We can do no more than present the circumstances under which it arises, and our own consciousness at once teaches us what is meant.

1. To proceed in this manner, then, I would observe that when I look upon a book, or any external object, I instantly form a notion of it, of a particular kind. I know it as an external body, numerically distinct from myself, of a certain form color and magnitude, at this moment and in this place existing before me. When I handle a book, I have the

same notion, the quality of color only excepted. This knowledge is called perception.

2. Secondly, I find that when the object of perception is removed, and the act of perception ceases, a knowledge of the object is still present to my mind. This is called a conception. Thus, the book which I just now perceived is removed, but the conception of it is still an object of consciousness. A cube which I saw is burned to ashes, but I have a distinct conception of its form and dimensions. I can recall to my mind the cataract which I saw last summer, the house in which I slept, or particular portions of the road over which I passed. In these cases, however, the conception is not simple; it is combined with the act of memory. I have not only the conception, but the assurance or belief, that at a certain time these objects actually existed as I now conceive of them.

3. But let us now separate this act of conception from the act of memory. We can conceive of a tree or a cataract without connecting it with the idea either of present or past existence. We are doing this continually in the course of our own thoughts. We do it when we read a romance. We are here continually forming images of things, places, and persons, which we know never existed. So, in a geometrical demonstration, we form for ourselves the conception of a figure, and proceed to reason upon it, though we have never seen it represented to the eye. A concept or concep

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The word conception is commonly used in two or three significations. It is employed to designate the power or faculty, the individual act of that faculty, and that act considered as an object of thought. On this subject Sir W. Hamilton remarks, "We ought to distinguish imagination and image, conception and concept. Imagination and conception ought to be employed in speaking of the mental modification, one and indivisible, con sidered as an act; image and concept, in speaking of it, considered product or immediate object.”—Note to page 263.

tion is, therefore, that representation or cognition of a thing which we form in the mind when we are thinking of

it.

4. Again, when we think of an act of the mind as thinking, willing, believing, or of any emotion, as joy or sorrow, we form a conception of it. We cannot think it unless we can do this. Hence, when a state of mind is spoken of which we cannot represent to ourselves in thought, we say we cannot conceive of it; that is, the words spoken do not awaken in us any corresponding conception.

5. Again, by the faculty of abstraction we may analyze the elements of these concrete conceptions, and combine them into general or abstract ideas. Thus, from several individual horses we form the general notion of a horse, meaning the genus, and having respect to no individual horse existing. These are general conceptions, or conceptions of genera or species.

6. We have also conceptions of general intuitive truths, such as the axioms of mathematics. We conceive of the truth that the whole is greater than its part, or that if equals be added to equals the wholes are equal. So we form conceptions of general relations, as of cause and effect, power, and many others.

7. Lastly, we are able to form images by combining into one whole, elements previously existing in the mind, as when a painter conceives of a landscape, or of a historical group. This form of conception is more properly styled imagination.

In all cases of conception where the act is completed, if I do not mistake, we form something of the nature of a picture, which the mind contemplates as the object of thought. I am aware that, in speaking and writing, when the terms are perfectly familiar, we do not pause and form the conception. Thus, we use the axioms, in demonstration, without pausing to reflect upon the words we employ, and yet we

use them with entire accuracy. Thus we speak of cause and effect, number, and various other ideas. When, however, we attempt to dwell upon any one of these ideas, so far as I can observe, we form a concept of it in the mind. Thus, when I think of the term horse as a genus, and dwell upon it in thought, there is before me, as an object, a concept of such an animal. So, if I think the axiom the whole is greater than its part, two magnitudes corresponding to these terms present themselves before me. From this remark, however, must be excepted those cases in which we recognize a truth as a necessary condition of thought, as duration, space, and ideas of a similar character. Even here, however, we find the mind from its natural impulse striving to realize something which shall correspond to a concept.

Of conceptions thus explained it may be remarked in general:

1. In conception there is nothing numerically distinct from the act of the mind itself. From the analogies of language we are liable to be misled in thinking of this subject. We speak of forming a conception, and of forming a machine; of separating the elements of a conception, and of separating the parts of an object from one another. As in the one case there is some object distinct from the ego, we are prone to suppose that there must be also in the other. There is, however, in conception nothing but the act of the mind itself. We may, nevertheless, contemplate this act from different points of view; first, as an act of the mind, or as the mind in this particular act, and, secondly, as a product of that act which we use in thinking. There is, however, numerically nothing but the act of the mind itself.

2. Conception enters into all the other acts of the mind. In the simplest sensation there is, for the time being, a knowledge or a notion, though it may remain with us not a

moment after the object producing it is withdrawn. We can have a knowledge of our own powers only as we have conceptions of them. We can remember, or judge, or reason, only as we have conceptions. In fact, all our mental processes are about conceptions. Of them, all our knowl edge consists.

3. Our conceptions are to us the measure of possibility. When any proposition cannot be conceived, that is, is unthinkable, we declare it impossible or absurd. Thus, if it be said that a part is greater than the whole, that two straight lines can enclose space, or that a change can take place in a body while all the conditions of its existence remain absolutely the same, I understand the assertion; but when I attempt to form a conception of it, that is, to think it, I find myself unable to do so. I affirm it to be impossible. On the other hand, I may think of a communication between the earth and the moon. In the present state of science it is impracticable, but it is within the limits of thought, and my mind is not so organized that I feel it to be impossible. This case, is, however, to be distinguished from the unconditional, the incomprehensible. This, from the nature of our intellect, we know to be necessary; it is not contradictory to thought, though to grasp the conception is impossible. In the other case we are able to comprehend the terms, but we are unable to construe them in thought; in other words, the relation which is affirmed is unthinkable.

4. In simple conception, or where it is unattended by any other act of the mind, there is neither truth nor false hood. I may conceive of a red mountain, of a blue rose, of a winged horse, but the conception has nothing to do with my belief in the existence of either of these objects. If the conception is united with an act of judgment or memory, then it at once becomes either true r false. In the concep