Those who have seen errors or sketches of truth in conceptual fictions have certainly seen something: because (without incidentally anticipating at this point the theory of errors, or that of sketches or aids to the search for truth) it may at once be admitted, that conceptual fictions also sometimes become both errors and obstacles, and suggestions and aids to truth. But because a given spiritual product is adopted for an end different from that which rightly belongs to it (thereby becoming itself different and giving rise to a new spiritual product), we must not omit to search for the intrinsic end, which constitutes the genuine nature of this product. The portrait of a fair lady, white as milk and red as blood, which the prince of the story finds beneath a cushion by the help of the fairy, may serve as an incentive to make him undertake the journey round the world in search of the woman in flesh and blood, who is like the portrait and whom he will make his wife; but that portrait, before it is an instrument in the hands of the fairy, is a picture, that is to say, a work of art, which has come from the hands, or rather from the fancy, of the painter; and must be appreciated as such. Thus conceptual fictions, before they are transmuted into errors or into expedients, into obstacles or into aids to the search for truth, have, before them, a truth already constructed, toward the construction of which, therefore, they cannot serve; whereas that truth has served them, for they would not otherwise have been able to arise. They are, therefore, intrinsically neither obstacles nor aids to truth, but something else, that is, themselves; and what they are in themselves it is still necessary to determine. [Sidenote: _Practical character of conceptual fictions._]