It is difficult to say what support is rendered to practical Ethics by the theory of Evolution. According to it, Ethics is a history and a prediction; but failing the existence in any individual (as the result of a growth) of the moral sense for which Evolution professes to account, the prediction only applies to future generations; and it is difficult to see that practical Ethics has for such a person any intrinsic authority. And even if the moral sense, and social pressure (which are respectively the intrinsic and the extrinsic authority, for practical Ethics) are sufficient of themselves to enforce moral conduct, then the understanding of how they both came to possess such a power of command, lends them no additional authority, but rather tends, at first sight, to detract from their sacred prestige. The confidence of the philosopher is however soon restored, when he considers that despite the failure of his theory to intellectually establish moral enforcements, nevertheless, the great forces which have produced both the intrinsic and the extrinsic ethical authorities are still at work, and must more and more prevail. If these are natural growths the movement in the hearts of men, and in societarian organization, will ever prevail over and above all reasoning about them. Individual opposition and restiveness will be levelled before the might of the advance. The individual must obey or perish; indeed he must himself change and become part of the coercive power. Thus it will be found that the apprehension which Mr. Spencer expresses in his preface, as to the loss of a controlling agency in the decay and death of an older regulative system is not met by the establishment of a new controlling agency which takes the place of the discarded authority, but may be met by the fact disclosed in evolution, that whatever authority men may recognise, nay, even if they do not recognise any, it is all the same--they are part and parcel of an onward growth against which it is useless to rebel. The moral authority is the conviction of the inevitable. Thus evolution dispels the fear of a moral anarchy by showing the necessity for the existence of present and future moral order, ensured alike by extrinsic social organization, and by a no less certain prevalence of intrinsic motives. Thus, though evolution lends but little additional theoretical force to moral argument, it shows forth the power of natural ethical authority, and declares with convincing efficacy, "magna est veritas et prævalebit."