The subject is not new, and reflections will crowd upon every reader. The notions, in the mean time, which we entertain, even in speculation, upon a subject so important, cannot be entirely fruitless to mankind; and however little the labours of the speculative may influence the conduct of men, one of the most pardonable errors a writer can commit, is to believe that he is about to do a great deal of good. But, leaving the care of effects to others, we proceed to consider the grounds of inconstancy among mankind, the sources of internal decay, and the ruinous corruptions to which nations are liable, in the supposed condition of accomplished civility. SECTION II. OF THE TEMPORARY EFFORTS AND RELAXATIONS OF THE NATIONAL SPIRIT. From what we have already observed on the general characteristics of human nature, it has appeared that man is not made for repose. In him every amiable and respectable quality, is an active power, and every subject of commendation an effort. If his errors and his crimes are the movements of an active being, his virtues and his happiness consist likewise in the employment of his mind; and all the lustre which he casts around him, to captivate or engage the attention of his fellow creatures, like the flame of a meteor, shines only while his motion continues; the moments of rest and obscurity are the same. We know, that the tasks assigned him frequently may exceed, as well as come short of, his powers; that he may be agitated too much, as well as too little; but cannot ascertain a precise medium between the situations in which he would be harassed, and those in which he would fall into languor. We know that he may be employed on a great variety of subjects, which occupy different passions; and that, in consequence of habit, he becomes reconciled to very different scenes. All we can determine in general is, that whatever be the subjects with which he is engaged, the frame of his nature requires him to be occupied, and his happiness requires him to be just. We are now to inquire, why nations cease to be eminent; and why societies which have drawn the attention of mankind by great examples of magnanimity, conduct, and national success, should sink from the height of their honours, and yield, in one age, the palm which they had won in a former. Many reasons will probably occur. One may be taken from the fickleness and inconstancy of mankind, who become tired of their pursuits and exertions, even while the occasions that gave rise to those pursuits; in some measure, continue; another, from the change of situations, and the removal of objects which served to excite their spirit.