Such, unquestionably, is the great practical object of all philosophy. If it increase the happiness and virtue of human kind, it must be allowed to have fulfilled, to human beings, the noblest of earthly ends. The greatness of this primary object, however, perhaps fixed too exclusively the attention of the moral inquirers of antiquity, who, in considering man as capable of virtue and happiness, and in forming nice and subtle distinctions as to his supreme good, and the means by which he might attain it, seem almost to have neglected the consideration of his intellectual nature, as an object of mere physical science. Hence it happens, that, while the systems of ancient philosophy exhibit, in many instances, a dignity of moral sentiment as high, or almost as high, as the unassisted reason of man could be supposed to reach, and the defects of which we perhaps discover only by the aid of that purer light, which was not indulged to them, they can scarcely be said to have left us a single analysis of complex phenomena of thought and feeling. By some of them, indeed, especially by the Peripatetics and Stoics, much dialectic subtilty was employed in distinctions, that may seem at first to involve such an analysis; but even these distinctions were verbal, or little more than verbal. The _analytical investigation_ of the mind, in all its complexity of perceptions, and thoughts, and emotions, was reserved to form almost a new science in the comprehensive philosophy of far later years. If, however, during the flourishing periods of Greek and Roman letters, this intellectual analysis was little cultivated, the department of the philosophy of the mind, which relates to practical ethics, was enriched, as I have said, by moral speculations the most splendid and sublime. In those ages, indeed, and in countries in which no revealed will of heaven had pointed out and sanctioned one unerring rule of right, it is not to be wondered at, that, to those who were occupied in endeavouring to trace and ascertain such a rule in the moral nature of man, all other mental inquiries should have seemed comparatively insignificant. It is even pleasing thus to find the most important of all inquiries regarded as truly the most important, and minds of the highest genius, in reflecting on their own constitution, so richly diversified and adorned with an almost infinite variety of forms of thought, discovering nothing, in all this splendid variety, so worthy of investigation, as the conduct which it is fitting for man to pursue.