Although it may seem strange to include it in logic, poetics is nevertheless a part of rational philosophy and, in fact, is a distinct kind of argumentation. The purpose of all argumentation is to lead one to a new truth from previous knowledge. Poetry, although the weakest form of argumentation, does lead us to new truths. In doing so poetry has its own means of inducing assent to truth. As a part of rational philosophy, poetics should consider at least the means the poet uses, the objects the poet represents, and the end of poetry. We shall be using the terms "poetics" and "poetry" in a generic sense, as referring to any work of fine art employing words and sounds as means of representation.
The poet seeks to induce assent to truth by a pleasing representation of truth. Just as forms and colors are used by the painter in his representations, so words and sounds are used by the poet. He uses words chiefly to compose metaphors and similes, whereby, because of the lack of intelligibility in contingent things, a poetically imaginative meaning is read into things. He uses sounds in a pleasing manner by the employment of rhyme, alliteration, rhythm, and so on.
Now the poet presents his truth in terms of an image, for men naturally delight in images. Indeed, in the very making of the image, the poet makes his meaning. Hence, one will attain this truth, not directly in itself, but in the image that the poet presents. By representing the image in a pleasing manner, the poet leads one to agree with his judgment. For example, Shakespeare induces us to accept the universal judgment that uncontrolled ambition can lead to a man's downfall by giving us a particular representation of this in the person and action of Macbeth. From the acceptance of this particular representation we are led to accept the universal judgment. We realize that what has happened to Macbeth could happen to ourselves or to anyone.
The image of the poet is in the rational order; his image is presented in words, which can be known only by the intellect. In an intimate union of sense and intellectual knowing lies the strength and appeal of the poet, for while he does attain something universal, he attains it strikingly, vividly, and familiarly, as it is realized in the singular. We see, as it were, the universal concretized. Through the image in words, a truth is conveyed, a truth contained in a judgment. Herein, then, lies the significance of the phrase "argument of the play" that we find stated as an introductory summary in a program. This rationality of the poetic image is not attained by the images of the other fine arts. For this reason, poetry is the most intellectual of the fine arts and is the only one that has argumentation, properly speaking.
The objects the poet represents are human actions of agents who are necessarily either good or bad, since it is the first property of human action to be good or bad. Consequently, in his work of representing human actions, the poet must present a judgment bearing on the morality of these acts; the poet cannot abstract from the first property of human action. This does not mean, however, that he "moralizes" art in the sense of imposing morality upon art, but that in treating the proper matter of his art he must, as artist, observe faithfully the nature of that matter, namely, that some human actions are good and others are bad. He has the obligation as artist to represent good human action as good and bad human action as bad.
The intrinsic end of poetry is to represent truth and to cause delight in the knowledge of this representation. In realizing this end, the poet also introduces an order into the movement of the passions. For example, in a tragedy the poet arouses and resolves the appropriate emotions of pity and fear. We experience a certain satisfaction in this exercise of the emotions and a relief from the turbulent disorder often found in them.
The extrinsic end of poetry is to make men disposed to acquire virtue and to avoid vice. This is accomplished both by the acceptance of the judgment made by the poet and by the ordering of the passions (the poetic catharsis of the emotions). More men are led to the acquiring of virtue through representations than they are through reasoning bearing directly on morality. Accompanying this extrinsic end, there is the recreational effect of release from the cares and frustrations of everyday life. By introducing something of a rational order into a course of events, the poet relieves the irrationality that we often face in our daily lives.