These facts I sum up as follows: the distinction between moral good and evil; the obligation of doing good and avoiding evil; the faculty of accomplishing or not this obligation. In brief and philosophic terms the Moral Law, Duty, and Liberty. These are the natural, primitive, and universal facts which constitute human morality; it is by reason and by virtue of these facts that man is a moral being.
I have not here to enter into a discussion of these same facts; I do not occupy myself at this moment with systems which disregard or deny them, in whole or in part; all the three facts, or any one of the three. The partisans of the system of independent morality admit them all, as I do; the question between them and myself is this, whether or not, whilst rendering homage to the true principle of morality, they fully comprehend its signification, and accept its results.
It is the characteristic and the honour of man that he is not satisfied with merely gathering facts which relate either to himself or to the external world, but that he seeks to know their origin and object, their import and bearing.
In morals, as in physics, statistics are only the point from which science sets out; it is only after having well observed facts, and having verified them, that we have to discuss the questions which they raise, and the further ultimate facts which the facts already ascertained contain and reveal. The fact of human morality, such as I have just described it in its three constituent elements, the Moral Law, Duty, and Liberty, cannot fail to suggest these two questions: Whence proceeds the moral law, and whence is its authority? What is the sense, and what the ultimate result to the moral being himself, of the fulfilment or violation of his duty; that is to say, of the use which he makes of his liberty? No philosophical system can either suppress or elude these questions; they present themselves to the mind of man as soon as he directs his attention to the moral character of man's nature. I propose to consider in succession the three constituent elements of this great truth, so as to determine rightly its source and bearing.
Moral law has neither been invented by man, nor does it spring from any human convention; man, by acknowledging it, admits that he has not created it, that he cannot abolish or change it. Political and civil laws are diverse and ever varying; they depend in a great measure upon time, place, social circumstances, or human will; when men adopt or reject them, they do so with the feeling that they are the masters of them, to deal with them accordingly as their interests or their fancies suggest.