_Conclusion._--So far as regards the origin of the ideas in question, it is not easy to draw a dividing line, then, between the two classes, marking the one as _external_, the other as _internal_. Both are of external origin, and equally so, in this sense--that they both depend, and equally depend, on some previous exercise of sense as the occasion and condition of their development. Both are of internal origin, in another sense--that they are both awakened in the mind--are both the product of its own activity.
_Difference lies in what._--The difference is not so much that of externality or internality of origin, as it is a difference of character. The one relates to objects of sense, which can be seen, heard, felt; the other to matters not less real, not less obvious, but of which sense does not take direct cognizance. In either case they spring from the constitution and laws of the mind. Such is my constitution that external and material objects, affecting my senses, furnish me ideas relating to such objects. And such is my constitution that certain relations and qualities of things not directly cognizable by sense, and certain realities and facts of an æsthetic and moral nature, likewise impress my mind, and thus awaken in me the idea of such relations and realities. The objects, the relations, the realities, exist, they are perceived by the mind, and thus the first idea of them is obtained. Color exists, and the eye is so constituted as to be able to perceive it, and thus the idea of color is awakened in the mind. So right and wrong exist, and the mind is so constituted as to be able to perceive and recognize their existence, and thus the idea of right is awakened in the mind. The faculty we call perception in the one case, original conception in the other.
TRUTHS AND CONCEPTIONS FURNISHED BY THIS FACULTY
_Primary Truths and Primary Ideas as distinguished._--The faculty in question may be regarded as the source of primary beliefs, truths, cognitions, intuitively _perceived_, and also of primary and original conceptions, notions, ideas, also intuitively _conceived_.
The difference between a conception or idea, and a belief or truth, is obvious. The notion of existence, and the knowledge or belief that I, myself, exist, are clearly distinguishable. The idea of cause, and the conviction that every event has a cause, are distinct mental states. The one is a primitive and intuitive conception, the other a primitive and intuitive truth. Every primary truth involves a primitive and original conception.