Yet these melancholy cases of self-deception are not to be remedied by mere explanations of the delusion; on the contrary, the practical use to be made of definitions and distinctions and descriptions in matters of religious feeling, is to exhibit the necessity and to enhance the value of more available tests of sincerity. Thus, for example, if it appear that, in times like the present, when religious profession undergoes no severe probation, the danger of substituting some species of enthusiasm for true piety is extreme, there will appear the greater need to have recourse to those means of proof which infallibly discriminate between truth and pretension. This means of proof is nothing else than the standard of morals and of temper exhibited in the Scriptures. No other method of determining the most momentous of all questions is given to us, and none other is needed. We can neither ascend into the heavens, there to inspect the book of life, nor satisfactorily descend into the depths of the heart to analyze the complex and occult varieties of its emotions. But we may instantly and certainly know whether we do the things which he whom we call Lord has commanded. [1] The metaphysico-devotional "Confessions" of the good Bishop of Hippo may perhaps not unfairly be placed at the head of this very peculiar species of literature. The author is reluctant to name some modern works which he might deem liable to objection, on the ground of their giving encouragement to religious sentimentalism, lest he should put into the mouth of the irreligious a style of criticism which they would not fail to abuse. He is aware that he runs a hazard of this sort in advancing what he has above advanced. He can only say that he thinks the subject much too important in itself, and too intimately connected with the theme of this Essay, to be passed in silence. And he cautions the irreligious reader, if the book should fall into the hand of any such unhappy person, not to suppose that the author would either disparage the important duty of self-examination; or speak slightingly of those mental struggles which will ever attend the conflict between good and evil in the heart that has admitted the purifying influence of the Holy Spirit. What he pleads for, is, that self-examination should always have reference to tho Christian standard of temper and conduct; and that spiritual conflicts should consist of a resistance against evil dispositions or immoral practices. What he fears on the part of religious folks is, a forgetfulness of meekness, temperance, integrity, amid the illusions—now gloomy, now gaudy—of a diseased brain.