First Part of the Philosophical Theory of Religion, remark.

The conflict between the two above-mentioned hypotheses rests on a disjunctive proposition; man is (by nature) either morally good or morally bad. But it readily occurs to every one to ask whether this disjunction is correct, and whether one might not affirm that man is by nature neither, or another that he is both at once, namely, in some parts good, in others bad. Experience seems even to confirm this mean between the two extremes.

It is in general, however, important for Ethics to admit, as far as possible, no intermediates, either in actions (adiaphora) or in human characters; since with such ambiguity all maxims would run the risk of losing all definiteness and firmness. Those who are attached to this strict view are commonly called rigourists (a name that is meant as a reproach, but which is really praise): and their antipodes may be called latitudinarians. The latter are either latitudinarians of neutrality, who may be called indifferentists, or of compromise, who may be called syncretists.

The answer given to the above question by the rigourists is founded on the important consideration: That freedom of elective will has the peculiar characteristic that it cannot be determined to action by any spring except only so far as the man has taken it up into his maxim (has made it the universal rule of his conduct); only in his way can a spring, whatever it may be, co-exist with the absolute spontaneity of the elective will (freedom). Only the moral law is of itself in the judgment of reason a spring, and whoever makes it his maxim is morally good. Now if the law does not determine a man’s elective will in respect of an action which has reference to it, an opposite spring must have influence on his elective will; and since by hypothesis this can only occur by the man taking it (and consequently deviation from the moral law) into his maxim (in which case he is a bad man), it follows that his disposition in respect of the moral law is never indifferent (is always one of the two, good or bad.)

Nor can he be partly good and partly bad at the same time. For if he is in part good, he has taken the moral law into his maxim; if then he were at the same time in another part bad, then, since the moral law of obedience to duty is one and universal, the maxim referring to it would be universal, and at the same time only particular, which is a contradiction.

When it is said that a man has the one or the other disposition as an innate natural quality, it is not meant that it is not acquired by him, that is, that he is not the author of it, but only that it is not acquired in time (that from youth up he has been always the one or the other). The disposition, that is, the primary subjective source of the adoption of maxims can be but one, and applies generally to the whole use of freedom. But it must have been itself adopted by free elective will, for otherwise it could not be imputed. Now the subjective ground or cause of its adoption cannot be further known (although we cannot help asking for it); since otherwise another maxim would have to be adduced, into which this disposition has been adopted, and this again must have its reason. Since, then, we cannot deduce this disposition, or rather its ultimate source, from any first act of the elective will in time, we call it a characteristic of the elective will, attaching to it by nature (although in fact it is founded in freedom). Now that when we say of a man that he is by nature good or bad, we are justified in applying this not to the individual (in which case one might be assumed to be by nature good, another bad), but to the whole race, this can only be proved when it has been shown in the anthropological inquiry that the reasons which justify us in ascribing one of the two characters to a man as innate are such that there is no reason to except any man from them, and that therefore it holds of the race.