In some ways, indeed, it may be held inferior to Chronicles and Characters; we look in vain for anything like the terrible intensity of the night-scene in Irene, or for any such passages of massive and memorable writing as appeared, here and there, in the earlier work, and made it not altogether unworthy of its model, Hugo's Legend of the Ages. But it becomes evident, on the most hasty retrospect, that this earlier work was a step on the way towards the later. It seems as if the author had been feeling about for his definite medium, and was already, in the language of the child's game, growing hot. There are many pieces in Chronicles and Characters that might be detached from their original setting, and embodied, as they stand, among the Fables in Song.
For the term Fable is not very easy to define rigorously. In the most typical form some moral precept is set forth by means of a conception purely fantastic, and usually somewhat trivial into the bargain; there is something playful about it, that will not support a very exacting criticism, and the lesson must be apprehended by the fancy at half a hint. Such is the great mass of the old stories of wise animals or foolish men that have amused our childhood. But we should expect the fable, in company with other and more important literary forms, to be more and more loosely, or at least largely, comprehended as time went on, and so to degenerate in conception from this original type. That depended for much of its piquancy on the very fact that it was fantastic: the point of the thing lay in a sort of humorous inappropriateness; and it is natural enough that pleasantry of this description should become less common, as men learn to suspect some serious analogy underneath. Thus a comical story of an ape touches us quite differently after the proposition of Mr. Darwin's theory. Moreover, there lay, perhaps, at the bottom of this primitive sort of fable, a humanity, a tenderness of rough truths; so that at the end of some story, in which vice or folly had met with its destined punishment, the fabulist might be able to assure his auditors, as we have often to assure tearful children on the like occasions, that they may dry their eyes, for none of it was true.
But this benefit of fiction becomes lost with more sophisticated hearers and authors: a man is no longer the dupe of his own artifice, and cannot deal playfully with truths that are a matter of bitter concern to him in his life. And hence, in the progressive centralisation of modern thought, we should expect the old form of fable to fall gradually into desuetude, and be gradually succeeded by another, which is a fable in all points except that it is not altogether fabulous. And this new form, such as we should expect, and such as we do indeed find, still presents the essential character of brevity; as in any other fable also, there is, underlying and animating the brief action, a moral idea; and as in any other fable, the object is to bring this home to the reader through the intellect rather than through the feelings; so that, without being very deeply moved or interested by the characters of the piece, we should recognise vividly the hinges on which the little plot revolves. But the fabulist now seeks analogies where before he merely sought humorous situations. There will be now a logical nexus between the moral expressed and the machinery employed to express it. The machinery, in fact, as this change is developed, becomes less and less fabulous. We find ourselves in presence of quite a serious, if quite a miniature division of creative literature; and sometimes we have the lesson embodied in a sober, everyday narration, as in the parables of the New Testament, and sometimes merely the statement or, at most, the collocation of significant facts in life, the reader being left to resolve for himself the vague, troublesome, and not yet definitely moral sentiment which has been thus created. And step by step with the development of this change, yet another is developed: the moral tends to become more indeterminate and large.