Finally, of this kind is an old German genealogical tree, in which the last representative of a very ancient family thus expresses his determination to live his life to the end in abstinence and perfect chastity, and therefore to let his race die out; he represents himself at the root of the high-branching tree cutting it over himself with shears. In general all those symbols referred to above, commonly called emblems, which might also be defined as short painted fables with obvious morals, belong to this class. Allegories of this kind are always to be regarded as belonging to poetry, not to painting, and as justified thereby; moreover, the pictorial execution is here always a matter of secondary importance, and no more is demanded of it than that it shall represent the thing so that we can recognise it. But in poetry, as in plastic art, the allegory passes into the symbol if there is merely an arbitrary connection between what it presented to perception and the abstract significance of it. For as all symbolism rests, at bottom, on an agreement, the symbol has this among other disadvantages, that in time its meaning is forgotten, and then it is dumb. Who would guess why the fish is a symbol of Christianity if he did not know? Only a Champollion; for it is entirely a phonetic hieroglyphic. Therefore, as a poetical allegory, the Revelation of John stands much in the same position as the reliefs with _Magnus Deus sol Mithra_, which are still constantly being explained. § 51. If now, with the exposition which has been given of art in general, we turn from plastic and pictorial art to poetry, we shall have no doubt that its aim also is the revelation of the Ideas, the grades of the objectification of will, and the communication of them to the hearer with the distinctness and vividness with which the poetical sense comprehends them. Ideas are essentially perceptible; if, therefore, in poetry only abstract conceptions are directly communicated through words, it is yet clearly the intention to make the hearer perceive the Ideas of life in the representatives of these conceptions, and this can only take place through the assistance of his own imagination. But in order to set the imagination to work for the accomplishment of this end, the abstract conceptions, which are the immediate material of poetry as of dry prose, must be so arranged that their spheres intersect each other in such a way that none of them can remain in its abstract universality; but, instead of it, a perceptible representative appears to the imagination; and this is always further modified by the words of the poet according to what his intention may be. As the chemist obtains solid precipitates by combining perfectly clear and transparent fluids; the poet understands how to precipitate, as it were, the concrete, the individual, the perceptible idea, out of the abstract and transparent universality of the concepts by the manner in which he combines them.