thence deduce his impulses, which are commonly the true efficient causes of men's conduct; and without which the motive itself would not have become a motive. Let a haunch of venison represent the motive, and the keen appetite of health and exercise the impulse: then place the same or some more favourite dish, before the same man, sick, dyspeptic, and stomach-worn, and we may then weigh the comparative influences of motives and impulses. Without the perception of this truth, it is impossible to understand the character of Iago, who is represented as now assigning one, and then another, and again a third, motive for his conduct, all alike the mere fictions of his own restless nature, distempered by a keen sense of his intellectual superiority, and haunted by the love of exerting power, on those especially who are his superiors in practical and moral excellence. Yet how many among our
