The fine arts, as observed above[14], are all of them calculated to give pleasure to the eye or the ear; and they never descend to gratify the taste, touch, or smell. At the same time, the feelings of the eye and ear, are of all the feelings of external sense, those only which are honoured with the name of _emotions_ or _passions_. It is also observed above[15], that the principles of the fine arts are unfolded by studying the sensitive part of human nature, in order to know what objects of the eye and ear are agreeable, what disagreeable. These observations show the use of the present chapter. We evidently must be acquainted with the nature and causes of emotions and passions, before we can judge with any accuracy how far they are under the power of the fine arts. The critical art is thus set in a fine point of view. The inquisitive mind beginning with criticism the most agreeable of all amusements, and finding no obstruction in its progress, advances far into the sensitive part of our nature; and gains insensibly a thorough knowledge of the human heart, of its desires, and of every motive to action; a science which of all that can be reached by man, is to him of the greatest importance. Upon a subject so extensive, all that can be expected here, is a general or slight survey. Some emotions indeed more peculiarly connected with the fine arts, I propose to handle in separate chapters; a method that will shorten the general survey considerably. And yet, after this circumscription, so much matter comes under even a general view of the passions and emotions, that, to avoid confusion, I find it necessary to divide this chapter into many parts: in the first of which are handled the causes of those emotions and passions that are the most common and familiar; for to explain every passion and emotion, however singular, would be an endless work. And though I could not well take up less ground, without separating things intimately connected; yet, upon examination, I find the causes of our emotions and passions to be so numerous and various, as to make a subdivision also necessary by splitting this first part into several sections. Human nature is a complicated machine, and must be so to answer all its purposes. There have indeed been published to the world, many a system of human nature, that flatter the mind by their simplicity. But these, unluckily, deviate far from truth and reality. According to some writers, man is entirely a selfish being: according to others, universal benevolence is his duty. One founds morality upon sympathy solely, and one upon utility. If any of these systems were of nature’s production, the present subject might be soon discussed. But the variety of nature is not so easily reached; and for confuting such Utopian systems without the intricacy of reasoning, it appears the best method to enter into human nature, and to set before the eye, plainly and candidly, facts as they really exist. PART I.