But the knowledge which we derive from the other source is of immediate and essential importance to men of every degree; and, without it, no individual could engage, with confidence, in any of the common transactions of life, or make any provision for his protection or comfort, or even for the continuance of his existence. These are the principles also treated of, in a former work, under the name of First Truths. They are not, like our knowledge of the other kind, the result of any process either of investigation or of reasoning, and, for the possession of them, no man either depends upon his own observation, or has recourse to that of other men. They are a part of his mental constitution, arising, with a feeling of absolute certainty, in every sound mind; and, while they admit of no proof by processes of reasoning, sophistical objections brought against them can be combated only by an appeal to the consciousness of every man, and to the absolute conviction which forces itself upon the whole mass of mankind. If the Creator has thus implanted in the mind of man principles to guide him in his intellectual and physical relations, independently of any acquired knowledge, we might naturally expect to find him endowed, in the same manner, with principles adapted to his more important relations as a moral being. We might naturally expect, that, in these high concerns, he would not be left to the knowledge which he might casually acquire, either through his own powers of investigation or reasoning, or through instruction received from other men. Impressions adapted to this important end we accordingly find developed in a remarkable manner,--and they are referable to that part of our constitution, which holds so important a place in the philosophy of the mind, by which we perceive differences in the moral aspect of actions, and approve or disapprove of them as right or wrong. The convictions derived from this source seem to occupy the same place in the moral system, that first truths, or intuitive articles of belief, do in the intellectual. Like them, also, they admit of no direct proofs by processes of reasoning; and, when sophistical arguments are brought against them, the only true answer consists in an appeal to the conscience of every uncontaminated mind;--by which we mean chiefly the consciousness of its own moral impressions, in a mind which has not been degraded in its moral perceptions by a course of personal depravity. This is a consideration of the utmost practical importance; and it will probably appear that many well-intended arguments, respecting the first principles of moral truth, have been inconclusive, in the same manner as were attempts to establish first truths by processes of reasoning,--because the line of argument adopted in regard to them was one of which they are not susceptible. The force of this analogy is in no degree weakened by the fact, that there is, in many cases, an apparent difference between that